Picked this interesting pocket watch up on eBay some months back.
Had a bit of a scrap for it against two other bidders, so even though there are no markings anywhere, I guess they had an idea of what it might be too!

Sterling Silver case and Very thin for its time at 11.0 mm caseback to crystal.
Marked .925 Swiss Silver, with casemakers mark LW in a square, plus a letter 'R' at the bottom.
Index marked 'Avance - Retard' so not made for English speaking market.

Screw set saphire(?) jewels to train cocks, all screws highly polished, and nicely finished throughout - even the lever is highly polished.

Only marks on the movement are on the dial plate under the dial - Deposé - Brevet - 308038.

The only 'giveaway' on the movement as to what its pedigree might be, is the regulator lever!
It's the classic 'curved' lever as used on Cortebert's Cal 354 ebauches which was also carried over onto the cal 540 ebauche Cortebert supplied to Rolex.
I've Never seen this lever used on any other marques.

Suffers a 'sticky balance' so it's in the 'pending' tray until I've more time to play with it.

John

Very slim case, and even slimmer movement!

JW.

Movement.

JW.

Telltale Cortebert-Rolex curved Index lever

Good find John!

I wish I know a small fraction about those watches, I wouldn't know a good one from a bad one.

Tom

Thanks Tom,

You know, when I first posted the topic on my butchered Rolex miltary PW way back when I first joined IHC185, I'd no idea about the Cortebert-Rolex collaboration.

It was only browsing for Rolex 'parts' watches (fat chance) on fleabay that I happened upon the tie up being mentioned in a listing description.

I went straight to my 'watch bits' boxes and turned up a Cortebert movement that was a dead ringer for my Rolex - right down to the curved index.
I'd agonised over that watch for years, and I'd all the bits sitting right there under the bench to fix it up!

I swapped the balance and lever from the Cort to the Rolex and darn me if it didn't kick right off and run.
Anyone that's ever messed with many Swiss movements trying to swap bits and find some that fit, will know that this revelation comes close to winning the lottery!

Spotting this watch though was just pure luck, found trawling 'similar items' from an ended listing.

In the end though, it all comes down to what you play with most and building knowledge on your subject!
You guys know American watches inside out, whereas I'd end up buying a Heinz 57 product!

I'm always amazed when reading some of the 'pitfalls' watch topics how you guys can tell a watch put together from a box of donors.

John