[Ron Ramirez]

Ron;
  If it appears to have left the factory with part 78 and 79  in place there must be a reason for them, though that's the first time that I have seen a pair of resistors between each leg of the power transformer primary and ground,

Now, potentially the resistors might be used to discharge the interwinding capacitance, I am not sure why, but suppose this is an especially capacitive xfmr that gets charged to some voltage that can give you a little tickle, someone complained and they decided to discharge it.

Yes, this set had the resistors, but one was connected across the line instead of from one side of the line to ground!

Okay, you guys have convinced me about the resistors, and I'll put new ones in their place - only they will be connected between each side of the line and ground as the schematic indicates.

I was thinking along the same lines as Arran regarding caps (73) and (74):

As for the ones on the plates of the rectifier tube, parts 73 and 74, maybe those are there to remove some sort of power line transient that was common in South American countries at the time?

In any event,  I have decided to leave those two caps out. So now, all of the paper caps have been replaced with new caps stuffed inside original (or original-type) sleeves. All resistors save three (78 and 79, plus one other) have been replaced. The dial lamp sockets are rebuilt. I only need to rebuild the electrolytic condenser cans, reinstall those, and attach a power cord and it will be ready to try out.