Success!
As I was going through the instructions in reverse order to pull out the Left (A side) C4S board on page 66 I realized that instead of instead of the Black wire from C3 being wired into the breg I had soldered it into dB.
I corrected it, checked that all the other wires are in the correct location on the A and B boards and did all my resistance checks.
The weird measurements are gone.
The tubes have been carefully inserted all the way into the sockets.
The voltage checks are also correct now.
In the morning, I'll put it into the system and see if it sings.
Thanks again for all the feedback and calm encouragement.
