Tubes Asylum: Fisher 50AZ by pigeon

I recently decided to put into service a long dormant Fisher 50AZ (which was fine before forced retirement, but also had survived several moves) for a mono system.

I checked the tubes with a not-so-reliable tester, sniffed around a little bit, and then plugged it into a variac. Everything seemed OK up to about 60V; but, then the fuse blew. A check revealed that one of the 12AU7's had "fogged" at the top with an easily visible crack in the envelope at the pins (A Bugle Boy, alas! RIP!).

Next thing to do was to peek at the innards a bit more carefully. Looking around the base of the socket of that cracked 12AU7, I could discern something I had not noticed before, since it was somewhat hidden between the chassis wall and, which looks like, the power supply board: very close to the pins of that tube on that board was a large (1.5") black cracked "resistor," with some white residue at the crack. On the one end of that "resistor" there are 4 bands (brown-grey-yellow-grey) on the other end a yellow band. The other 3 farther away on that board seem to be OK. There are also 2 smaller resistors(1"), that seem to be OK.

Elswhere in the amp are 2 pieces of 20u 150WV, one of which has a slight discoloration, ostensibly due to some past leak; the other has none.

Of course, I cannot ascertain the status of the 4 aluminum cans, without a voltage chart or even a schematic.

My question is, would the replacement of that cracked "resistor" be enough? How would one determine the wattage of it (the smaller ones also have a yellow band on one end)? Or, should one avoid turning this thing on without replacing the 4 electrolytic cans as well? Where can one find those? I can give their numbers. What about the other caps underneath? They are not really that many and look to be relatively easier to replace.

I would greatly appreciate any help you can offer. Also,where could I find a schematic and other information on this.

Many thanks.