Bought dead on ebay, to have a look at. Turned out it was just bunch of dead preamp valve, guy had reloaded it with JJs and they died after estimated 50 hours use.
Front of it, 5150 MKI style, but reverb option.
Random tested parts box valves I stuffed in, the Infinium sorts out the bias for them. Works fine by ear, not sure sticking a probe in won’t interfere with its function, so didn’t.
Inside, the infinium part is the board on the back of the chassis with bunch of push connectors. Small board with ribbon cable is the reverb. Modular inside, would guess lots of stuff in common with other models in the line.
Clsoer shot of the small modular boards, along with showing that the main circuit is pretty normal through hole pcb, not mystical magic that cannot be fixed like is often claimed about these amps. Ribbon cable is data from digital reverb.