I haven't really studied the schematic yet, I've looked it over some and the set seems really simple. Unfortunately out west in the rural areas we're limited as to what is available as far as swap meets and hard parts. Maintenance parts are easy to get.
In earlier sets like this one, same as in larger radios with more serious acoustics Philco did not use the field coil as the main filter choke (that also would require hum-bucking wire) but did use separate large chokes (also in 20, 70, 90, 16, 116 and its permutations, and all those early consoles whose chassis look similar to yours) that look like a mid-size transformer.
This set takes 3 type 24 tubes, is there a difference between a 24 and a 24A or are they both the same type of tube?
The 24A was the replacement for the 24, and as a general rule they can be interchanged except in some Crosley's that used the 24 as an oscillator.
The 24s in this case look to be part of the tuning on the model 77 Philco, I was told there was an amperage difference between the 24s and 24A. In this application am I okay with the 24A or should I continue looking for type 24's?
24A's should do fine in your radio. RCA designed them as a direct replacement for the 24's but with some improvements (faster warm-up), except they would no longer work as an oscillator, which the tube was never designed to do in the first place.
So far I have been able to get all the tubes except the 45's which seem to go up in price and get expensive. The other part it is missing is the cover that goes over the top of the type 24 tubes. Is this going to be a hard part to find?