drumfx, that serial (456xxx) would be expected to be 1980. Your drum is the "lacquered brass" shell 2 to 1 model. Listed in the '79 catalog on the VDF and in K.O.'s earlier post in this thread. Per DrCJW the lacquered brass shells had a high copper content and are sometime mistaken for bronze or copper. It is in fact Slingerlands "lacquered brass". Hope that helps.
Totally helps, i had never seen one of those before...Any idea of their street value?