As a novice, I would be hard pressed to identify a true 1st or 2nd generation Yamakichibei from a good Norisuke. The third generation, however, is easily identifiable by a cherry blossom stamp after his mei. Unfortunately, this Sakura Yamakichibei did not always stick to the traditional style of his school, finding a good example can be difficult. Not that it helps much, but I try to judge a tsuba based on its merits and not just the signature.
Jason