[Electronic M]

IIRC you have not replaced the bumblebees and tubular ceramic caps in that set yet...Vertical troubleshooting 101 replace EVERY cap in the vertical stages first (no exceptions, total original capacitor genocide!), check for proper operation, then go after tubes and resistors.

See all the caps circled in my edit of your picture? If any of those are in the vertical stage or any vert capacitors currently installed look like them then the vertical will probably not work completely right.

Lytics can cause problems in the vertical (and sometimes are the only problem), but papers can be as bad or worse. On a set this old it is a miracle it works as well as it does now with those lousy old caps.