Thanks everyone for all the input and feedback!
Think I'm going to hold off on the RI for two reasons. After playing with the amp, cranking the amp with an attenuator is still pretty loud to get the break up. Current thinking is a separate house/practice amp. It would be nice to find a two channel practice amp to cover both the fender cleans w/ & w/o reverb on one side and the marshall crunch on the other. In the same light the idea of a modified Super Reverb with a Fender on one side and a Marshall on the other sounds very appealing.
Seems a hard wired older version would lend itself to this more readily.