Sams service manual, download, pdf. It's all you need to service or restore most of the under dash 45 players. Most companies re-branded the AP1 or made modifications to get by the patent laws, but they are still very similar to the AP1.
If you have a "sparky" or bad motor, I have a good substitute. It requires a little modification, but it fits right in and because it has no brushes, it won't create noise in the output. I can supply pix of the one I did and measurements for the adapter. There are no mods necessary to the unit itself.