(Sorry if this doesn't relate...still might help. -Rick B.)
See picture, the 'House' Tektronix '465 Scope shown has a dial, I think it's called a 'vernier dial knob':
The inner knob, 0 through 9, causes the outer skirt to move, 1/10 the way in it's dial, for each time the inner dial completes a run past top center, positive clockwise, or decrease by counterclockwise.
So I guess that's a 100 step vernier altogether.
But elsewhere the special knob I remember has a little rectangular window cut-out, where another dial underneath had it's scale partially showing. So the scale rotated, underneath that opening in the outer stationary skirt.
Yeah, WWII salvage and historical items, and the small electronics surplus places,...some of those business owners, dead now, (sorry). Anybody remember
QUINTRONICS in West Berkeley industrial area?
And hey...; Maybe try get that question in, to Computer History Museum (?)