Saltwater or freshwater? I assume you have looked in Stanley Olsen (1968), who has the bones and scales of a few common types of fish found at archaeological sites in the U.S.
I know that when we had a large collection of fish scales from an archaeological site in the coastal zone of south Louisiana our archaeozoologist used the comparative faunal collection at Tulane University to identify them. I recently read that either the University of North Carolina or maybe the University of South Carolina had a comparative collection too.
Stanley Olsen. 1968. Fish, Amphibian and Reptile Remains from Archaeological Sites. Papers of the Peabody Museum of Archaeology and Ethnology, Vol. 56, No. 2. Harvard University, Cambridge.
Richard Daniels. 1996. Guide to the Identification of Scales of the Inland Fishes of Northeastern North America. New York State Museum Bulletin 488.