I was wondering what happened to the right control key in your second pic. Now that I see your description, I guess it was because it is silk screen printed on PBT.
Bottom row keys are useless on MX switch boards unless you mod them. Bottom row and center stemmed CapsLock key would be needed to fit a modern keyboard. Otherwise pretty nice looking caps! White on black Cherry double shots are my favorite.
The caps would have come from G81-8000 POS boards. And the delete key might have been used a lot in the application. These are better than caps from G81-7000 or 1800 because of long right shift and correct R2 profile of Delete, End, PgDn keys. Do you not have number pad keys?
Anyways, good luck with your sale!