I just got a really nice pocket watch in, from about 1912, extremely thin, with a killer .900 silver case and beautiful milled edging Unfortunately, the, I think, beautiful dial is in reasonably dreadful condition and the movement doesn't exactly what is called 'work' and to me has suspect jewels? The movement measures 38mm across and I am not sure that either the dial or movement are all that rare. Though I'll bet they aren't usually found in as bad condition as this. There seem to be lots advertised on ebay emanating from The Argentine for only about 4 or 5 times what they are worth. A thought occurred to me: I have had a nice movement lying in a drawer for about 40 years which, every time I take it out, annoys the hell out of me because it steadfastly refuses to stop ticking! I had been looking for a nice case for it for at least a decade. It is 40mm across. Does anyone have a suggestion as to how I could just switch the movements please so that I can use it? I have seen lots of watches using a spacer, as original, to account for the slight size differential between the movement and the case?
How hard can it be, right? I mean, you installed your own garbage disposal so swapping a movement has got to be easy-peazy! Where is that DIY thread?
Unless your donor movement & dial are the same as the originals - which is clearly not the case - it will require a lot of modification, if it is even possible at all.
Which one are you implying is garbage? (There is that screw sticking out by the regulator which might get in the way a bit, and one just by the 4)
You'd be better off just hunting the same movement again, pocket watch movements aren't worth much so you'll find a good one relatively easily.
Why would you switch an Omega movement and a Zénith one? I would rather keep the original movement - which looks absolutly genuine - and try to find another original dial. There are lots of movements with dials like yours on eBay. Concerning your Zénith movement, it is not rare - even if it has a nice regulator "col de cygne". So I would try to find a watch which has the same movement, but in bad shape, and switch them - or use the movement you already have as a donor.