Never had the pleasure to work on a Majestic, but I am building up my muscles for when I do.
These TRF's follow the same pattern, one amplifier after another until you get to the detector, so several stages will be essentially the same to trace out. Somewhere in there is something open or miswired. Does it look like anyone was in there before you?
In your underchassis picture, looks like something burned down in the lower left corner?