Patek Philippe

Thanks

Do you have the broken mainspring? Just having the old one is probably enough for the right guy to find or make a new one that will suit. There are reference books that list the characteristics of mainsprings (length, width, thickness and strength) and I have some of those but don't do this sort of thing often enough to know what you're looking for.

OR

Someone needs to have a few drawers like this and the willingness to spend possibly a few hours searching for the right one:

Also, FYI very few watchmakers I know will touch a woman's watch like this because they are too small, parts aren't easily available, and there's zero water and shock protection so the first few times the watch is worn it gets knocked around and broken again.

Decide how much you are willing to spend (make sure it's enough to pay for all the time he could have been doing Rolexes with eyes closed) and guarantee the watchmaker you will pay him whether it works properly or not when it's finished. That's the competition for getting this nice little diamond-set watch running again.

I wish there was a more positive answer. 

Good luck

Cazalea