Vernier calipers

[oldel]

Yeah, the thing up top is a thumb screw (with shaft), I'm missing the thing at the bottom that the thumb screw actually screws into.
Like you said, small thumb screws are hard to find in smaller sizes, but whatever the receiving "thumb nut" is, that's even harder to find!

Anyway, it obviously wasn't an expensive unit, as I found similar to them for $30. But looking for an upgrade, something with good stainless steel, something not digital, something under $100