If it is belt drive it is not a Model 45, or 33. If there is no chain at all, just a belt, it is probably a 430 or 590. We have a number of threads here about both - you might find them informative.
It would be helpful if you post a picture, which will show whether it is a 430 or a 590. Most parts are difficult to get for both, but the most crucial ones should be available.
