Ok, the chassis is completely recapped now:
There was one totally-buried wax cap (circled in red) that I had no chance of replacing, in place. I moved it to an electrically-equivalent location (the rightmost, vertical orange-drop shown above):
The on/off switch was gunked/oxidized to the point that it no longer made contact. I had to split it open and clean it. While at it, I deoxxed the volume control carbon and wiper, so it should be scratchy-free:
Will put it all together next weekend probably. Hope it works!