Got impatient to see something new so put a Sound City aside to get into this. Hurried front shot before I took it apart shows, at least I remembered this time.
Turns out unfamiliar is scary.
Bit friendlier after dusting:
SS front end, guess the ECC81 is the PI, does seem to dirty up on the front end OK. Hard to follow circuit round by eye, so didn’t. Looks like the filter caps have been done, crudely, but done. Sticker backs this up
From the other side, less dust here. Gave it a cleaning, tested valves, works OK, pots bit crackly, but can’t get into them to spray, exercising them helped. £250 if ya want it.