[wa2ise]

You don't necessarily need the schematic to replace wax paper caps. Helps, but not critical. But you should replace one cap at a time. That is, remove an old cap, and immediately install the new cap of the same ratings +-10% with the same or higher voltage rating. Before you forget where the old cap connected to. I just snip out the old cap with some of the old wire lead still attached to the locations it connected to. You could just "J hook" the old wire lead to the new cap's lead and solder it. Just keep the physical location of the new cap the same as the old one. And try to make the J hook connections reasonably straight, and not likely to touch something else and short out. Don't try to remove all of the old wire lead from tube sockets or terminals. Those are rather fragile and tend to break under the stress of trying to remove leads.

Ceramic caps (the ones that look like discs) don't usually go bad, so you don't normally need to change them.

The caps connecting the chassis to the powerline are not essential, worst that happens without them is that you might pick up some noise or hum on some AM radio stations. SO you could just remove them and wait for the X or Y replacements to arrive later. Just keep notes where they went.