The easiest issue to address is the high filament voltage. I measured it to be about 10% high. This makes sense. In 1940 house current was lower than today, about 110 V vs 120-125 V today. A power transformer designed to generate 6.3 V in 1940 wold now show closer to 7 V, about what I measured. To solve this I have step down transformers at both of my prewar operating positions. I decided to add a third.
As expected the 10P filament voltage dropped to 6.3 V but B+ still remains high. This may be because the replacement electrolytics I used in the power supply are larger than the originals. I'll need to work on this.
Addendum - The high B+ was a simple fix (but I'm not a fan of the engineering trade off behind it). I had removed the 6L6 modulator while testing CW. It turns out that this tube loads down the power supply, even in CW mode. I plugged the 6L6 modulator in and B+ now looks about right.