My Grandfather's Watch — An Investigation

Phase One

The Questions

When the watch came into my hands, I knew almost nothing about it. Only that it was old, and that it was gold. Before any research could begin, I had to decide what I was actually trying to find out.

When was it made?

Who made it?

How does it work?

Which country is it from?

How valuable is it?

A note on watchmaking

Why these questions are harder than they sound

A watch from the early 20th century rarely tells you its story directly. Dials were often unsigned. Case makers, movement makers, retailers and importers were frequently four different companies in three different countries. The answer to "who made it" can have five correct answers depending on what you mean. Provenance is detective work — and the clues are stamped, in miniature, on metal.

To get answers to these questions, we can examine the watch for clues.

Phase Two

The Watch

Here is the watch itself. Take your time with each image — click to zoom in. As you look, note what you see. Anything that feels like a clue, however small. Type it into the evidence box below each photo.

01 — Dial & Case Front

What do you see?

02 — Case Back & Serial

What do you see?

03 — Interior Hallmarks

What do you see?

04 — The Movement

What do you see?

05 — Side Profile

What do you see?

06 — The Hinge

What do you see?

Phase Three

The Research

Each piece of evidence we flagged becomes a thread to pull. Some lead to clean answers. Others open small mysteries of their own.

Material

The "18.75" stamp

Stamped inside the case is the mark 18.75. This is a continental purity mark: 18-carat gold at 75% purity — in other words, 750‰. It is unambiguous.

To understand why this stamp matters, it helps to know where hallmarking comes from. European hallmarking began in 1275 in France under Philip III, and in 1300 in England under Edward I, whose "leopard's head" mark struck at London's Goldsmiths' Hall gave us the word hallmark. Over the centuries that followed, assay offices across Europe developed a standardised language of tiny stamps: a purity mark (what metal it is), a maker's mark (who is responsible), an office mark (which assay office certified it), and often a date letter (what year it was tested). Every mark on this watch belongs somewhere in that 750-year-old system — which means, if you know how to read them, the case itself is a signed document.

Finding — this is a solid gold watch.

Import hallmarks

The twin "F" marks

In the position reserved for British import hallmarks sit two stamps showing twin F's — the assay mark of the Glasgow Assay Office. Cross-referencing Glasgow's date letter tables gives us the year the watch was submitted for assay: 1929–1930.

Finding — we now know when the watch was made.

Casemaker

The hammer and "112"

A small stamped hammer containing the number 112 is a French-style poinçon de maître — a master's mark — that traces to Ducommun, a known casemaker. But here we hit a small wall. The surviving registration records for the hammer-only variant of the mark don't extend back to 1929, even though Ducommun is registered with the later hammer stamp.

Finding — a confident identification with a small mystery attached.

Serial number

0848459 11

The back of the case carries the serial 0848459 11. It looks definitive, and it isn't. In this period, serial numbers are notoriously unreliable as an identification source — they behave more like patent numbers than modern serials, often recycled or reassigned.

Finding — a dead end, but a useful one.

The dial

No signature. No brand name.

The dial is blank of any maker's name. This feels wrong to a modern eye, but research into the period tells a different story. In the 1920s, a gold watch was the desired object. The brand was secondary — sometimes deliberately absent — because the metal and the craftsmanship spoke louder than a logo.

Finding — the unsigned dial is period-correct, not suspicious.

The movement

Swiss made, three adjustments

The movement is distinctive in style and marked Swiss Made with three adjustments for precision — a specification that was uncommon in 1929 and a signal of a genuinely high-grade watch. Following the architecture and layout of the calibre leads us to Cyma Tavannes, almost certainly the Hunter 1 ébauche. A manual-wind movement.

Finding — a top-tier Swiss movement from a serious house.

"RA SR"

A translation for the UK market

Engraved on the movement: RA SR. These are French watchmaking abbreviations translated for use on Swiss watches imported into the United Kingdom — regulator and second marks repurposed for the English-speaking market.

Finding — the watch was prepared specifically for the UK.

The J·C stamp

The sponsor's mark

The most important stamp of all sits in the sponsor's position: J·C. In British hallmarking, the sponsor's mark is the legal declaration of responsibility — whoever's initials sit there is guaranteeing to the Crown that the metal is what it claims to be. It is not necessarily the maker; it is the party accountable for the object's provenance.

A search of the Glasgow Assay Office registers returns a swathe of watchmakers and retailers with "J.C" hallmarks around 1929. Which one is ours?

Finding — this is the thread we have to pull next.

Phase Four

The Lead

Eight clues on their own are just eight clues. The work begins when you start combining them — when the individual findings get stacked into a single search and suddenly point somewhere unexpected.

I had three strong handles from the research: a pair of initials (JC), a movement maker (Cyma), and a year (1929). Taken alone, each one is ambiguous. Stacked together, they form a search specific enough to be interesting.

JC cyma 1929

→ One result worth a second look: a Sotheby's auction listing

The listing is a Cartier travel watch, sold at auction by Sotheby's. The catalogue description reads:

Manual winding movement, running at the time of cataloguing. Dial signed Cartier. Interior of case behind watch with British hallmark for Glasgow, 18 carat gold (750‰), date letter g for 1929. Initials JC for Jacques Cartier, numbered 319. Inscribed SFG Brev. Dep. Tavannes Watch Co Swiss, numbered 0828496 46. Sotheby's — lot description

Sotheby's listing of the Cartier travel watch

The cousin watch

Line up the two watches side by side and the family resemblance is impossible to ignore. Not identical — but clearly from the same period, the same workshop lineage, the same moment in watchmaking.

Attribute	My grandfather's watch	Sotheby's Cartier (1929)
Dial	Silvered, unsigned	Silvered, signed Cartier
Dial hands	Blued steel, Breguet-style	Blued steel, Breguet-style
Railroad track	Minute chapter in railroad style	Minute chapter in railroad style
Numerals	Roman, slim serif	Roman, slim serif
Movement	Tavannes / Cyma, manual-wind	Tavannes Watch Co, manual-wind
Case	18ct gold, hinged back	18ct gold
Crown	Onion-style, fluted	Onion-style, fluted
Material	18.75 (750‰) gold	18 carat gold (750‰)
Import date	1929–1930	1929 (date letter g)
Import location	Glasgow Assay Office	Glasgow Assay Office
Sponsor's mark	J·C	J·C (Jacques Cartier)

Every single box either matches exactly or sits one step away. The assay office is the same. The year is the same. The metal is the same. The movement maker is the same. The sponsor's initials are the same. That last one is the quiet bombshell — Sotheby's catalogued their J·C as Jacques Cartier, the brother who ran Cartier London in the 1920s and was the family member responsible for the firm's British output.

What the lead triggered

On the strength of this comparison I walked into a watch shop in Eindhoven with photos and the Sotheby's listing. They took one look and pointed me to Cartier Amsterdam. Cartier Amsterdam took the watch in for authentication and kept it for three months, passing it through their internal channels and across to Paris. Last week I got the answer: they don't have enough evidence to confirm what it is either way, and their recommendation was to escalate to Cartier London so it could be checked against the original Jacques Cartier records.

The decision

Why I stopped here

I've decided not to send it to London. Honestly, I don't think it's a Cartier. The dial is unsigned, the Cartier houses in Paris and Amsterdam couldn't find it in their records, and the most likely story is the more interesting one: in 1929, Cartier was already becoming fashionable in London, and a good anonymous gold watchmaker used a thematically similar design, a Cyma Tavannes movement, and a respected casemaker to produce a piece in the same spirit. Not a fake. A contemporary, from the same world, sold through the same assay office in the same year.

But I still don't know who J·C is. And the overlap with the Sotheby's Cartier is stark enough that I'm not fully closing the door — I'm just choosing to stop chasing it, restore the watch, and wear it.

Phase Five

The Man Behind the Watch

All of this research — the hallmarks, the assay offices, the auction twins — matters because of whose wrist it was on. My dad gave me this story on 13 January 2026, in honour of his father.

Archibald Geschwindt
Born in 1903
Attended Moberley School — previously known as Harrow Road School
Worked for the Great Western Railway out of Paddington for more than 45 years
He was given another watch to commemorate his service to the railway
A Smiths De Luxe, with an engraving on the back

A life at Paddington

Archie joined the Great Western Railway as a young man and spent more than forty-five years with the company, working as an accounting clerk out of Paddington station. When he started, the GWR was still privately owned — one of the "Big Four" British railways, operating its own locomotives, its own stations, its own livery. By the time he collected his long-service watch around 1963, the GWR had been nationalised into British Railways' Western Region for fifteen years, but the old name still stuck in the offices at Paddington, and the culture of the place hadn't really changed.

The work itself was the quiet machinery behind the railway: ledgers of freight receipts, passenger revenue reconciled station by station, wage sheets, supplier accounts, and the endless columns of figures that kept trains running on time. A forty-five-year career as a clerk is not a glamorous story. It is a story of showing up. Every working day, for most of a lifetime, to the same building at the end of the same platforms.

Paddington Station, Great Western Railway

The Smiths De Luxe

The Smiths De Luxe is notable for being the other watch that summited Everest in 1953 — worn alongside the Rolex Explorer on Sir Edmund Hillary's wrist.

… but that's a story for another day.