[morzh]

I also found those and preserved them. Good high resistance wire (maybe Constantan?)
Reason? Convenience maybe. After all all those Philco parts were only manufactured for own production and there was a multitude of backelite block cap assemblies; nothing wrong with putting a resistor in really. Less soldering. Probably the same reason as with cap assemblies.
Plus I think the backelite block idea itself was: you get free soldering posts to hold wires.