Thanks for all help!
I will take a clamshell lock, if and when I find one.
Guess it was drop to the higher price of making them, so now they are all gone and part of gun making history.

Well, not sure about the Sauer sidelocks, just asking to learn more about the German made double rifle/drilling and style´s they used.

You got a Sauer sidelock drilling?

Got a photo to?