It's a 20 chassis.
The 20 has that square metal can filter cap.
The 21 has a round single 14mfd mounted where the square is. there's a cover plate to cover the square hole in the chassis w/a round hole to mount the round cap.
> Up for offer vintage 1931 Philco cathedral tube radio model 20E.
Nowhere on the label does it say "20E" - it says "MODEL 20".
> Knobs are original.
No, that tuning knob is not original (too large).
Early production 21 sets did indeed use leftover 20 chassis, and the label stated "MODEL 20". I owned one once, and while the label did read MODEL 20, the label was slightly different from this older label. And my 20/21 also had the same knobs as regular Model 20 sets, not the rosettes they switched to later on.
Ron
So, is it a 21? (I guess that was my question). Considering we do know they used 20 chassis. Even if with a wrong knob.
technically.....so you have a suspicion it was combined from two radios? And was not sold as a 21?
Then again if this is a valid way of being a 21, then it is a 21, right? Even if it wasn't sold as one? I mean, if I swap a bad rusty chassis in, say, a 70 for a good one from another 70, that will not make a radio non-authentic? So should be this one too then?
https://www.radiomuseum.org/r/philco_cat..._20_e.html
So, there was a 20-E model after all.....it is probably a European version as it says "230V 50-60Hz".
Otherwise it is exactly the same as 21.
The guy found that and this is why he though it was a 20-E, but his is 21.
Any Philco model number ending in "E" or "EZ" indicates a set made in USA but intended for export.
While the Radiomuseum set is an export model, the set linked in your first post above (the eBay ad) is not.