[morzh]

ALL CAPACITORS, with the exception of the micas, HAVE TO GO.

This goes especially to the big can in 20.

Here's my recent experience of potted cap cans: the RCA R-73. When measuring the capacitance, I found the 10uF caps were still 10uF, and the others were fairly close in values to their original one, with the exception of 2 or 3 of them.

So I decided to try to power it and see how they work (RCA can, unlike the Philco 20 or 16 one, is a very hard to take out). Well, I had a huge amount of hum. I did not remove the can, I just cut the wires and replaced them right to the places where the wires from the can would go. After that the radio performed just fine.

And, in Philco 20, it is VERY easy to remove the can, and you do not even have to desolder the panel. The can itself comes out from the metal shallow part around it that also holds the phenolic panel with contacts; the wires to the rivets get cut the same way as you would in a regular backelite block.
Removing the tarred innards may be a bit messy and challenging, but this would be done with the can conveniently removed from the chassis. The replacement caps go right in the panel, and then the freed of the tarred caps metal shell simply goes back.
If it were not for the tar block being a bit stubborn to come out, I'd say this one is no harder than to restuf a regular small backelite cap, and considering the number of caps addressed in one fell swoop, it is even less time-consuming.

As for the looks, and some folks would not even be able to tell 70 and 90 apart, were it not for the feet on 90 instead of the continuous trim base on 70, I prefer the 90 to se as it has a bit different top arch shape, it peaks a little, and to me it is a bit nicer looking than the 70.
The 20 Deluxe is indeed very handsome, I have it. I think, I have most of the 20s: regular, deluxe and the console with the grillwork (no, I do not have the 220 with the phonograph).