I'm in Omaha, NE and I've been a tinkerer for a very long time. Lately I've been trying to find one of my old AIWA portables, or something very much like it, and the Goodwill auction site had a couple examples that were close to the kind I used to have. I got them for less than $20 each and of course both of them have problems with the tape mechanism, most likely belts. Radios work and they bring in a strong stereo signal. One of them makes motor sounds when I push play, but of course there is no activity in the tape mechanism. The other makes no sounds at all when I press play. Anyway I'll take my tech discussion to that section but the forum insisted I introduce myself first. The two devices I have are an AIWA HS-JS145W and an AIWA HS-JS215. I found the belt kit for the 215 pretty easily, but can't seem to find information on a belt kit for the 145W, though I did find a service manual for it.
Check out turntableneedles.com they have a great search engine. Most USA Sellers have Russell Industries PBR Belts, if they don't have it check Fixyouraudio on the front page of the forum, he's been a great supporter of the hobby. Good luck with your repairs. I've got a box with around 100 of those more basic models, I should rebelt them and move them on to members.