(Solved is an 842109/07) Do we think this is a 842101? Missing case back.

G___ · Mar 8, 2026

Hello All and Sundry,

Do we think this is a 842101? It has caliber 42 and the same general look and feel.

That's what the reverse image robots suggests, albeit with the earlier logo-type. I picked this up for very short $ from a general junk auction a sometime last year. It is missing the case back, so no ref or sn. Bench ran great for a few days.

Suggestions on where to obtain some type of case back are welcomed (I wouldn't care if said Timex, frankly). I'd looked around for a case back and my jeweler (who has a hundreds/thousands of case backs) had a poke around. Couldn't find one.

Thanks and regards,

Carlton-Browne · Mar 9, 2026

The obvious place to scour would be Ebay but you'll never have 100% certainty until the postman delivers. Most 842101/542101 have these lugs (you've likely already spotted this)

And the lugs on yours are different. I have this 842101 where the lugs are different again:

So the old UG maxim that the case reference is always the case reference whereas the dials/handsets can be different doesn't seem to apply here. If the lugs are different the so too can the caseback. There is this 542122 which just might work (it's a gamble) but the price is high for your needs (but it could be worth googling other case references in a close sequence).

https://www.ebay.co.uk/itm/326283316991

If you do buy something from Ebay you might want to negotiate a right of return if it doesn't fit. Also bear in mind that if you were to purchase a whole watch then the gold-plated versions seem to be cheaper and that you'd have a spare movement for future servicing. Finally you might want to check the Japanese auction sites as this model seems to have been popular there (but you can probably write off any chance of being able to negotiate a right of return).

I can measure the diameter of my caseback if you think that might be useful.

G___ · Mar 9, 2026

Carlton-Browne
The obvious place to scour would be Ebay but you'll never have 100% certainty until the postman delivers. Most 842101/542101 have these lugs (you've likely already spotted this)

And the lugs on yours are different. I have this 842101 where the lugs are different again:

So the old UG maxim that the case reference is always the case reference whereas the dials/handsets can be different doesn't seem to apply here. If the lugs are different the so too can the caseback. There is this 542122 which just might work (it's a gamble) but the price is high for your needs (but it could be worth googling other case references in a close sequence).

https://www.ebay.co.uk/itm/326283316991

If you do buy something from Ebay you might want to negotiate a right of return if it doesn't fit. Also bear in mind that if you were to purchase a whole watch then the gold-plated versions seem to be cheaper and that you'd have a spare movement for future servicing. Finally you might want to check the Japanese auction sites as this model seems to have been popular there (but you can probably write off any chance of being able to negotiate a right of return).

I can measure the diameter of my caseback if you think that might be useful.

Many thanks for the considered reply and offer.

By my measurements, the caseback inner diameter I'm searching for is 26.40mm. Would be interested to know if yours matches.

Carlton-Browne · Mar 11, 2026

The external diameter of my caseback is 24.5mm.

The internal dimension as indicated in the following picture is 22mm

G___ · Mar 11, 2026

Carlton-Browne
The external diameter of my caseback is 24.5mm.

The internal dimension as indicated in the following picture is 22mm

Thank you!

Silversix · Mar 14, 2026

It's the 842109, they're in 32.5mm. The 842101 are in 31mm.

G___ · Mar 16, 2026

Silversix
It's the 842109, they're in 32.5mm. The 842101 are in 31mm.

Many thanks!

Carlton-Browne · Mar 16, 2026

With potentially a 542109 providing a cheaper caseback.

e.g. https://www.ebay.co.uk/itm/206126212621

G___ · Mar 17, 2026

Carlton-Browne
With potentially a 542109 providing a cheaper caseback.

e.g. https://www.ebay.co.uk/itm/206126212621

Much appreciated, thanks!

G___ · Mar 17, 2026

Located a seemingly identical 842109/07 on ebay, down the the crown which I'd through was replaced (unless they were both replaced, of course).

Now, to find any type of appropriate case back.

From: https://www.ebay.com/itm/236656099877

Screenshot 2026-03-17 at 09-43-38 Universal Genève 842109 Calibre Ug 1-42 Manual Winding Gene...webp

Screenshot 2026-03-17 at 09-44-21 Universal Genève 842109 Calibre Ug 1-42 Manual Winding Gene...webp

Screenshot 2026-03-17 at 09-44-02 Universal Genève 842109 Calibre Ug 1-42 Manual Winding Gene...webp