[Arran]

Is it a tuned RF amplifier stage or just a straight RF amp? I think that when you say two IF stages you mean two IF amplifier stages? Again there are two kinds with that, some use an extra IF amp tube but only two IF transformers and others use three IF transformers having an interstage IF transformer coupling the two IF amp tubes. Philco liked to use three IF cans with two IF amps in their sets, they also liked used twin triodes for mixer-oscillators with it especially in the 1940s. I have quite a few sets that used two IF amplifier tubes but with only two IF transformers, especially battery set built by Electrohome, I haven't really examined the circuit in each but I suspect that the IF amp tubes are capacitive coupled together.
I have two Philco hippo model sets with two different front ends, one uses the twin triode XXD/14AF7, but has two IF amps and three IF transformers, the other uses a tuned RF amplifier stage. I plan to get both sets restored and see which design works better, it may not be as easy to judges as I think.
Regards
Arran