[Arran]

The value of the cathode resistor does matter, the cap in parallel with it is not as critical, it's basically a bypass cap, it's to prevent degeneration in the amplifier circuit reducing the gain. A higher value cap will bypass lower frequencies, a lower value will bypass higher frequencies, if I remember correctly, but the difference between a .01, a .05, and a .25 is likely marginal in an IF amp. The purpose of the resistor is to raise the potential of the tube's cathode above ground, or more positive, to make the grid more negative since it is closer to ground potential.
With Philco there were not only different model numbers, but code numbers, and production runs as well, each code number denotes circuit variants, as well as the production run, though the latter is harder to find in most literature. I don't think there is any explanation for the difference in value of the cathode bypass caps other then Philco using what was available. I would try using a .05 uf cap if that's what you have on hand, voltage isn't that critical, you could use a 50 volt unit and it would be fine, but like most of us you probably have a bag of 400 volt or 630 volt caps.
Regards
Arran