[Chuck Schwark]

I'm sure those are contruction station marks, q/c and re-work markings, as well as final "ok". Since Philco used several outside cabinet shops, besides their in-house, cabinet marks will vary from jobbers. I know that the cabinet shop "number" was uaually in the cabinets too.

Ron has a listing of them here on his site.

I'm sure Ron and elucidate and or correct me. He is the Philco cabinet guru.

Chuck