I was so close, and then I created another problem for myself.

I asked this same question on another forum I'm a member of and a fella over there kindly sent me a pair of old stock mainsprings that he thought should do the job.

I got the watch apart, old broken spring out and the new spring in and reassembled. I thought something wasn't lined up quite right after initial reassembly (which it was not) so opened it up again and in the process of the second reassembly I managed to knock a jewel out of the bridge. I found it, and I think I can get it back in, but I do not have a jewelers screwdriver small enough to get into the screw slot. Time to buy some more tools......

You're exploring and experimenting far more than I would have. Good for you!

I had a broken watch, I almost had a working watch, but now I have a watch that is broken in a different way.

The way I look at it is that I've lost nothing and that I've learned a bunch of stuff I would not have otherwise.

I ordered another Wiha screwdriver that I think will likely still be too big that will be here tomorrow and then we go from there.

I've been looking on eBay and I have a sneaking suspicion that I can buy another bridge with the jewel in question installed already and be back on my way for low $$. Temped to "make the investment".

The Wiha driver I'd ordered got here and is still a skosh too big to fit the screw slots.

Found an old set of jewelers screwdrivers I forgot I had and the smallest one was a fit. Man those screws are SMALL.

Jewel is back in the bridge, bridge is back in the watch and the watch is wound and running as I type this!

Now to see what kind of time it keeps after I monkeyed with it. Not that it was that accurate to begin with but.....

So far, my watch is running fine albeit a little fast. I need to tweak the regulator a touch.

I bought a "good" set of jewelers screwdrivers to supplement my existing kit along with an Optivisor and a watch oiler.

I also located and installed a micrometer adjuster for the regulator that had been missing since before I bought this watch.

Needless to say, I now have a Gruen and an Elgin pocket watch each partially disassembled on my bench. Mainspring for the Elgin got here today, having trouble identifying what mainspring I need for the Gruen as I can't ID the movement number yet.

Need to locate a ratchet wheel for the Elgin as well as the existing one is short a tooth.

I've started buying watch books as well. I also remembered that I have two 8-Day aircraft clocks that don't work right around here somewhere.

Rabbit hole, here I come!

Great! Good for you. My eyes and shaking hands preclude my adventures into watch repairl