Good info.....I have a used JSS box set up with that exact configuration (down to the correct switches, per the in-service pics).
I have seen 3 different radios while looking at the footage (I won't count the 800 MHz one, as it was S. FL only in 1994), so I'm beginning to think it could have been any of the ones we've already listed.
My '93 definitely did not have one...but the '85 may have. I've got a switch for the PAC for the '93, and I'll probably end up using the convertacom with the built-in switch on the '85 (especially if I can find evidence of it being mounted in there).