Omega www caseback

This is either donor-watch territory, or lathe-work time. IF it were me, I'd see how close I could get it something on the lathe to make one and trial/error the connection interface (really the only important part).

Thats a tough one though, anything you'd get would lose the engravings.

Yep, likely quite expensive, AND take some patience. I got a feeling there aren't many of these watches out there where the value is low enough to part it out. So you might just have to troll the auction sites to hope you can get luckly. As far as I know, no one makes an aftermarket one.

But having someone professional make a case back as a one-off is also going to be pretty darn expensive I suspect. The tolerances for a case back are going to be tight enough that most machine shops are going to balk at the accuracy required (assuming you could even MEASURE that accurately enough!), which is why i mentioned hand-fitting.

In my case, if I had the watch case, I have a big lathe so I could do the hand-fitting and hopefully get it done well enough for me, but unless you have the equipment, you'll have to find a friend who does in a way they would do it for beer money 😁

ONE Option I thought about: model it up in CAD with reasonable tolerances, but with the interference-fit part (the outer side of the inner ring) oversized slightly. Then, get one of the common online CNC companies (xometry, PCBWay, etc) make you a handful.

Then, super glue one to something in your drill/makeshift lathe, and fine-tune it with sand-paper/lathes/rouge until it fits perfectly. This is effectively what I would do on the lathe, except with the 'easy' 90% already done 😀

Interestingly, see https://omegaforums.net/threads/fake-www-dirty-dozen-omega-redial-cal-28-movement.188496

I didn't realize there were fakes, I wonder if THOSE case backs are compatible enough to work with yours? Might be a source of a donor.