That wasn't a proper disc mount as such, more of an awkward clamp on a standard leg. I'm sure that the RC36 pro class could be ordered with a disc only leg. My mind tells me that was about 1998.
As above, the RC36 is your starting point really.
You can fit certain disc brakes (Hope, maybe Rockshox too?) to the earlier RC35 but it's a bit "Heath Robinson" in its set up and relies on various adapters/bodhes etc, it's not pretty....