400 alto

That's a high enough serial that the Nortons are likely gone, but it still should have the snaps. Unlike the earlier Bueschers, these had started to become pretty inconsistent. Can you describe the engraving?
I wouldn't want to be in it any more than about 400 ready to play and looking good if it has the horizontal rather than vertical engraving. With the vertical floral pattern it's worth more and more likely to be a player.

If it's local enough, I'd try it. If it doesn't play as it is enough to get a feel for it, I'd pass. If it plays and only needs a couple pads and a tweak...