OK I have the main ideas, but run into something Im not sure about (and probably get wrong). I got the "local star" concept. A filter cap that feeds a section of the amp, should have its negative lead tied to the 'grounds' in that section. Not sure what to do about what Merlin calls 'daisy chain', though. I think this is what I got wrong in the Fender Deluxe Reverb I hacked together.
So, if I put a few lugs on the chassis, for this amp I think 3, would that work like Merlin's drawing? One for the preamp, one for PI one for power tubes, and one power supply + first reservior cap. There would be no wire between the local stars, the chassis would serve that purpose?