I am not by any means an expert on wristlet cases. However-in my travels last Sunday to a few vintage shops and after finding only fair to middling watches it occurred to me I came across a very authentic brown leather wristlet for a medium to med-large mens pocket watch and I am nearly certain it is early 20th and possibly late 19th. I don't think it was very expensive though I did not ask. Sorry I've no pics but it basically looks like a very old but completely intact (and not rotted) version of what guys sell now-new ones-built to mimic the old. The strap itself may be a bit thinner but I do thinks its authentic.
So-I intend to return there for a brooch and just wondered if any of the ww1 conversion guys might be interested. Id have to post the asking price when Im there as I doubt the eccentric guy could find it as I did. Probably been there for decades. I don't know what 'real' ones are worth and would not be doing this for profit-just a favor that easily accomplished by me. Cost+ standard post would be all.Not even sure they are so desired . I may be imagining that they are more valued or harder to come by then they actually are-in which case I might just pick it up for my great-grandmothers never-seen 4-colour gold Elgin hunter cased 16 that has not been worn in decades because my mother got scared when she bumped it against table edge(on necklace) and 18k bezel popped. I had a new one made (whew! THAT was pricey!) so it sits a lot and is truly a work of art in near mint condition. But then a wristlet doesn't exactly show off a fancy watch case either.
However since am not super hot or in dire need for one-- if its of great interest here-to any Pw collector just shoot me a pm or answer here if its not breaking the hallowed wus community standards and rules. I'd be glad to text an image and price. He has a could of Mido Multifortes I wasn't into either but they may be good. Just <28mm -a bit small.