I have one of those frames, and figured it to be an '81 or '82. The pictures do not give any detail at all, but mine has aero shifter bosses and no rear derailleur stop. I assumed it was built for AX components? Mine is a 58cm and is quite light!! Haven't built it up yet, although I have had it for about five years!! (one of the many, many projects!!!).
Cheers,
Chuck Brooks
Malta, NY