From the toolboxes

[Dave H (MI)]

Three items. Two seem to be related as they spin and have a center hole of the same diameter. The third small item is unmarked.

 

[ihplowboy]

Diamond grinding wheel ???
Jim

 

[Butch(OH)]

While I can't say for sure the two larger pieces might be stone holder parts for a Bay State grinder. I have a tool grinder that uses similar mounting system

 

[KenH(MI)]

No clue on the small item, but the two large ones are diamond grinding wheels.

 

[tom upton]

Small item looks like what I call a land wheel for a tachometer. You stick it on the end of your tach instead of a center, lay it on the od of a drum or on your belt conveyor and it gives you surface speed, usually in feet per minute. Maybe the tach is in another one of those treasure drawers?

 

[Dave H (MI)]

The small item, I meant to post but apparently I didn't, is a Starrett speed measuring attachment. Measures flat surfaces like belts. Replaces the tips on their speed indicators. I found another of these grinding things with the same size center hole that matches the two others in the pic. This one is clearly an abrasive. Coarse. Have to see can I find some info on the machine these fit.