I noticed some corrosion on the plug and the cable is loose.
So I opened it up and found it's much worse than I realized. The pins are corroded, screws are very rusty and it's been poorly rewired.
Here's a nice, neat factory original for comparison. Now I can the see the rewired one is so loose because it should have a section of the vinyl outer jacket inside the plug.
After more examination, i decided to rewire it myself.
The point of no return
Here are the wires for AC line interlock, tube filament, audio, horizontal & vertical yoke, HV and video.