Crank knobs needed

[WA2ROC]

Not exactly for AM radio equipment, but someone out there just may have what I need.

I am looking for a pair of crank type tuning knobs with a 7/16" diameter shaft size.  They do not have to be the same, but I would like them to be at least 2" to 3" in diameter.

The shaft diameter can be as big as 1/4" and I can shim it with bras tubing if needed.

These will be used as a platen adjustment on an Alessi Probe station.  We just got one from our corporate surplus site and the knobs are missing.

Thanks!