[OZ4]

Going back to the rectifier tube with only 1 volt on the filament. Does this mean filament is not heating up? yes-no

Either way there must be a bad connection somewhere. Tube socket or maybe solder connections. 

This must be fixed first before any other troubleshooting can be done.

There should 5v ac to light up the filament on the rectifier.

And at the same time see some 300+ volts dc Filament to the xformer center tap at R58. Be careful here.

The filament of the rectifier has both 5vac and 300+vdc at the same time.