The Vintage Motor Cycle Club Library is the place to go. They will provide you with copies of an illustrated parts list, the 1930 factory catalogue, the appropriate maintenance manual, et, etc.
Its the biggest and best motorcycle library in the world and you don't have to be a club member to access it.
They are also a very appropriate club for you to join as they run the type of events you will want to ride your bike in.
Cheers,