My wife finds yard sale watches and has me change the battery, but then I open one, a tiny thing and it's not battery powered but there are layers of tiny tiny gears. Mind boggling. (pro tip, a "bench knife" has a tiny blade that's optimized for plying open watch cases)
I just want to make sure that this is what you are talking about:
https://www.google.com/search?q=bench+knife
https://cdn11.bigcommerce.com/s-ihwnd7z21q/images/stencil/12...
The term GP was looking for is "Caseback Knife":
https://diplomatwinders.com/cdn/shop/products/55035knife_102...
Ah, yes ... that seems more reasonable. Thank you.