WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
Curious why you are choosing this path as the CRC filtering and rectifier are all integrated on the PCB...Unless its a transformer issue...
I have seen people use the multi-pin round RF plugs - you will need something suitable for 500V A/C duty and at least 6 "runs" (2XHV 2X5V 2X6.3V) unless you are off-boarding the rectifier - OR - if you go SS rectifier you no longer need the 5V winding)
Use male and female plugs for the cable (male towards power transformer chassis and female plug towards output transformer chassis). http://www.mouser.com/Catalog/catalogusd/642/1332.Pdf
Then select the receiving plugs accordingly. You should have a wire for ground line as mentioned earlier by another member.