When rebuilding a vintage motorcycle, are there any parts that are easy to put on backward without realizing?
Dollar Bill is right. I would also add that a digital camera is one of the best things for rebuilding old bikes that ever came out. Get one and take TONS of pictures as you take things apart. Every time to unbolt a piece, take a picture of the next step. Also, start saving small containers and use them for each and every part you take off. The write on the container what is in there. There are lots of vintage bikes out there that only need to be carefully taken apart and cleaned. The actual mechanical repairs are often really minimal (not always). A little paint and upholstery, some new tires, intake seals, a battery, and a carb rebuild will often turn a total mess into something you can be proud to ride around.