Here is where I am at so far. I'm going the DIY clean route first to see if that gets any improvements with the noise floor and crackly attenuator. I am focusing on the pre-amp, as I've routed my modern AVR to the power amp inputs and the output is still pretty clean sounding. Maybe i'll change out the caps at a later date.

Once complete I'll let you know how it worked.

I will of course be blowing the unit out with canned compressed air and spraying the pots and switches with Pro Gold if I can get some.

I Found a really informative vid on youtube about how to do this, so enjoy.

Anyway, here is the unit assembled:

Here is the unit divorced:

Here is the preamp undressed:

Closeups of pots and push button switches:

Closeups of input Selector switch and volume attenuator: