Looks lie a #2 drop to me. #1 drop was basically -17 degrees, yielding a level extension with typical head angle. The #1 was a universal model use for road and track use when road bars were also steel.

#3 was the most radical drop, I do not think this one is if memory serves, I lost the URL but a CR member put together a Cinelli visual chart that shows much.

Later the 2a alloy stem became the track stem.

Looks in reasonable shape, the lack of a steerer binder bolt will hurt its big dollar value, we will see if the Buy it NOW alternative is too seductive....