If you’re going to work on watches, you might want to invest in some digital calipers. I would be lost without mine. I use them to measure jewel bezels, case bezels, crystals, staff dimensions, screws, mainsprings, train wheel pivots, wheel diameters, etc. With a push of a button, you can immediately convert millimeters to inches. Sure beats figuring it out on a calculator!
I just purchased these 4" calipers for $16.50 to the door. My old ones are 6" and just a little too large for watch repair. They are made in China but the quality is good. I've even run them through the demagnetizer and it didn't hurt the electronics.
You can do an eBay search by using "4 digital caliper" in the title only. You should see some with a starting price of $9.99. If you search for "4 digital calipers", you will find the same thing for $24.00 plus shipping. I would rather pay around $10.00 myself.
Looks like they have the mm to inch scale built-in!
You have a nice set there. Many of the ones I see at marts and on ebay have just enough corrosion or other damage that it makes the numbers hard to read. I've got a set similar to yours but but because of corrosion, they are hard to read.