What parts are you looking for? The Schwinn Graduate is a Chinese GY6 clone. It is sometimes hard to get parts for it at local scooter shops. The Graduate is a TNG clone and I have the manual if you want it. You can get all the parts on eBay. You just have to refine your searches. I hope this helps.
I am an authorized Schwinn Motor Scooter dealer. What parts do you need?
The Graduate 150 has a pretty stock GY6 engine, while the Graduate 50 uses a 139QMB engine. In either case engine parts are pretty widely available.
If you're looking for body parts (panels, etc.) you really should talk to your nearest Schwinn dealer. Schwinn is pretty good about keeping panels in stock, and while they fit quite a few models from other manufacturers, the colors are pretty unique.