I have a machine with a Fanuc 6M controller - and the main input keyboard has two duff keys. 1985 vintage so the key modules are the sort that push into a punched metal frame, then a pcb solders them all together - each module having two pins, (so they are a simple contact, not a hall effect type)
The modules bear the name Omron, and the model seems to be a B2R - they are about 12-15 mm square (hard to measure as they are installed in the machine vertically) with pins on about 4 - 5mm spacing. Quite deep as there is about
12mm from the support frame to the pcb and a further 13mm from the frame to the keytop which mounts on a 5'ish mm square spigot. Needless to say no trace of them on the Fanuc web site.
Anyone happen to have a similar vintage keyboard with these modules fitted that they'd be prepared to convert to beer tokens - or even a keyboard from a Fanuc Tape Cut Model M wire edm machine . . .(some hope!!)
(OK not model engineering but I know a lot of followers of this group have wide experience in industry.)