[Mondial]

Yes, I assume they ran short of 7J7's in production and used the equivalent 6J8G to fill in. Or did Philco get a really good deal on a lot of 6J8G tubes? 

I always wondered why Philco went back to the already obsolete 6 pin type 41 and 84 tubes, when octal and loctal equivalents were widely available. In the 37 models they switched to all more modern style octals, only to revert back to the older style tubes in later models.

The only thing I can think of is the old style tubes were cheaper and more available in quantity. Still it seems somewhat strange that you would design a radio in the 40's with the latest loctals and pair them up with outputs and rectifiers from the early 30's.