Did a little more work on this radio:
Mostly changed the B+ supply to a voltage doubler. Oh, it sags under load, but I still get around 150VDC.
Also changed the 8V supply to a big transformer rated for 15VCT @51A, and used a couple of 7A circuit breakers, one for each 8V output (the 7.5V reads 8V under low loading). Breakers intended I think for mil work, tested them with dead shorts (pop immediately) and a 2X overcurrent (kicks out in about 1 1/2 minutes). This transformer will have a low Thévenin equivalent resistance (like 0.04 ohms), so the voltage will have very small sag. But I definately need overcurrent protection, or else the wires will get hot like a Weller soldering gun element, if a short ever happens. Just like the house wiring protection.