What have you just BOUGHT?

[Godfrey]

Very nice. That serial number looks close to the time of the change from the Sonnar to Gauss. It is easy to tell which yours is by the size of the rear element. Sonnar has a much smaller rear element than the double Gauss. Both are very nice lenses.

This one is likely the double Gauss ... the rear element is quite large in diameter. 🙂

G