[Arran]

From what I can tell this series of Philco models with this chassis were not especially prone to transformer failures, I think that Philco was aware of the tolerances of these tubes, based on their experiences with car radios, and (unlike some of their competitors) respected them. In addition to keeping the maximum voltages and currents low by using #41 or 6K6 tubes for power outputs, most of the other tubes were loctals that used 150 milliamp heaters. One thing that these sets are known for is failed audio output transformers, I'm not really sure why but many have even vintage replacements in them.
Regards
Arran