[Arran]

In the Philcorepairbench there's a way described to fix those potted caps, where he simply warms it up and the whole thing can be pushed out, and then new caps are put inside and potted.

You don't have to repot the Bakelite block condensers, that was just to keep moisture out of the old condensers, the new replacements are made out of plastic or are already sealed up so they don't need to be potted. When it comes to the big condenser can it may or may not need to be repotted, I'm thinking it won't on a Philco but with some RCA ones the metal box will fall apart without the tar inside. The Philco ones also have sets of terminal strips on the bottom so you can attach the replacement caps to the inside of those strips.
Regards
Arran