I think he mentioned it was in a new Sauer text. I'd like to see the proofmarks. It's a frame as filed by Bernhard Merkel and I have assumed for some time that he sourced Sauer for the raw forgings and then he himself was sourced for longarms in the white at first and post WWI for firearms in the finished state by the Berlin makers such as Barella, Foerster, Geiger, J.J. Reeb, Ludwig Schiwy, etc. See the banner on Cabela's "Fine Rifles" page and there is a DR with a similar frame. Nice find and I'll have to see if I can get some tube pics.

Kind Regards,

Raimey
rse