The TCL will depend on what controller/drives is currently fitted, as they were available with anything ranging from a basic stepper system, upto a Fanuc servo system.

Without knowing that, it's a wild guess. Most of the stepper systems could be interfaced to a basic BOB, but the servo systems would be a alot more involved, with the easiest option probably be fitting new drives and motors.
There's also the issue of what tool changer is fitted, as again there were a few options..