Savage 64

Hello all new here but have a question. I have two savage model 64 rifles with wooden stocks. On the receiver it is stamped Savage 64 and nothing else. The two guns in question have barrels on them that do not have any dove tails cut into them for front and rear sights, they are only able to use scopes. I was wondering what model of the 64 this might be? Also what years these guns might have been made? All the other model 64's that I have seen have front and rear sights on the barrels. If anyone might be able to help me I would appreciate any information. Thanks