[old_tv_nut]

1) Are the tranformers that could cause trouble in the Admiral near the neck of the CRT, while they are closer to the front in this chassis? Maybe this set could benefit from shielding more of bell of the CRT.

2) Are the suspect transformer sources riveted in place or screwed? If screwed, you could try reorienting them, but my guess is they are in the best orientation as built.

3) All this speculation is probably superfluous because you have seen it good once - so I still think wiggling ground connections, transformer shields, etc. and putting strong pressure on them one way and another might find something.