It always surprises me how often all or part of stopworks are missing in clocks and watches. Have an old (200ish y/o) Neuchateloise in, nice piece with date and strike on demand. These things have monster mainsprings and this one was missing the stopworks. In the past if one came in missing them and the customer didn't want new ones made I'd do the service and send it out. New policy is if they don't want new ones they can take it elsewhere. I have nightmares about these barrels going nuclear, and winding up "right to the end" of these beasts will surely one day end with a broken spring end and the massive damage that can cause.
These often have slightly larger barrels and stronger springs for the strike train, and those also tend to do an extra turn of wind. The stopworks are simpler than maltese cross type, but need a friction spring under the geared piece to be sure they stay registered. The finger is friction fit in a tapered hole in the barrel arbor, seemingly simple but fiddly to make. I think the pic is decent enough to show "sonnerie" very ornately written in scratch on the strike barrel from a past service, maybe 100 years ago?
If i have the parts i am willing to share. I can't use them in a lifetime. And lots of the movements are in bad shape .But some parts look fine. Could be hard to sell if i can't guarantee they are 100% perfect either. So as we all tinker with watches in here and can inspect the parts i send. It's nice to help out . Some other time it's maybe me that is searching for some hard to find part.
I can in a couple days when I'm back at it, but trust me, nothing moves upon pulling it out. No set lever with a dimple, definitely not a split stem, it looks exactly the same. Had my boss look at it, too, and we're pulling our hair out. I'll keep ya updated, thanks oldhippy!