Re: 70's Fender Bassman 135...
I had the Bassman 70 for a couple of years. I had it modified so that ch 1 fed into ch 2.
Sort of like a boogie, it had 2 gain stages before the master vol, each with tone controls. Made for a pretty good 1 sound amp, I could get a lot of different sounds, just one at a time. Got rid of it when I went back to combos.
That's what I like about the Fender silverface amps, they're still handwired point to point, but they're not so collectable that modding them is a terrible sin.