When did Novak sights and Curved Trigger Guard come in?

[ACEd]

It appears all 40 and 10 were Curved Trigger Guard beginning 1990. And Single Stack Compacts appear to all be curved. But Full Sized 45 and 9mm and the 6906 mostly remained D shaped until later.

As to Novak I am guessing it was also phased in about the same time as I have seen 3906 with Novak beginning in 1991 but 3913/14 had Novak from the beginning.

 

[jsbethel]

I bought a brand new 5906 with Novak sights and curved trigger guard in the early months of 1992. I recently sold a round trigger guard 5906 with a SPEC ORD of 2149 so 91-92 appears to be the 9mm transition.

 

[Sevens]

Maybe this is a large frame vs small frame kind of separation?

I have NEVER seen a fixed sight 10xx that was non-Novak, and those guns started shipping in 1990.