Just wanted to add that I broke down my Retro Valve last night and it seems to match up with what is listed for the RT Valve.
Has anyone had any luck finding the Polyurethane -004 90A o ring needed in the on/off for the RT/Retro valve? McMaster-Carr has it in 70A, but not 90A. When I do a full rebuild in the next few days I am going to try the 70A version and see how that holds up. I am also going to try an off the shelf bolt bumper. I'll post up if it works or not and what I used.