Otis

I think "81a" is actually 1980. The others could be '81-'82.

OP, when the Wool Jersey site is back up search "Bianchi" as there is a '78 catalog posted that shows all the specs for the Rekord 745 and 748. I downloaded only the Specialissima pages or I would post it for you.

The 745 frame would be nice with period Nuovo Record parts, as it's not a bad mid-level frame. I'd actually rather see it built as a retro fixed gear than shod with that modern Campy wheelset. That's just wrong.