I don't Know how much this will help you,I have a
Aiwa M100u cassette deck. My belts melted away the same. I had 1 belt that's a thin long belt that goes around 5 pullys and 1 flat belt about .250 wide that goes from a motor 12v to a drive pully about 2" round.
I'm looking for belts too! Good luck!
Rob, N.Tonawanda, January 2011