Mystery Tool

This is probably not the right place but I thought it was worth a try. I bought this tool/gauge/jig ? from a tray of unidentified objects in a junk shop for £2. No idea what it is but it is well made and it crossed my mind that it may be related to clock or watchmaking.

It is about 40mm long and 20mm across the two plates. The plates have 10 holes of graduated sizes. The holes are counter bored so that there is a shoulder inside each except the largest. I you look at the other pictures you will see that the the plates are held together by a concealed spring but can be separated by pressing on the opposite ends. The thumbscrew could either be used to lock the plates together or set an exact separation when depressed.

There are no ID marks of any kind so maybe made by a toolmaker or clockmaker. I believe that it is nickel plated brass.

Anyone have any ideas or suggestions where else I could post this online to try and identify it.

Thanks, Chris

Thank you. I guess the "head" of the hand would be clamped between the plates aligned with a suitably sized hole?

Is it a commercially available tool or would someone have made it for themself?

Thanks. Crystal clear.

Case closed.