C64RLB7106BT
I may be wrong, doing this from memory, but isn't that the older MSF that uses the "suitcase" programmer and PROM? Think the PC programmable series (later ones) had an "X" as the middle letter in the model number.
If it is the PROM programmable station, check out BatLabs website. There are several guys that still program those earlier units though some of them are a bit pricy. They are excellent radios, however, and, especially for a repeater, programming is a one-time proposition.
Tom DGN