OK, some updates on the Sony Boombox:
I have managed to fix fast forward (it was a frozen gear, which cleared up with some WD40 and some EM-30L), and auto-reverse seems to be working more reliably now since I squirted some WD40 in the mechanism.
Unfortunately, while I was doing this, somehow the fuse for the AC cord blew, so now it will only work on batteries, which isn't a big deal, although I'll have to figure out why the fuse blew and find a replacement.
Otherwise, it seems to be in fine working condition now. Just gotta get new belts for the tape deck so it plays right (as is, it runs quite slowly, and in forward, it has lots of wow; it's more manageable in reverse, but it is still slow). I bought one of those "universal" kits from Amazon which is due tomorrow. I'll see if I can get any of those working, then this machine should work perfectly.
c