Hi Tom,
In a week or so I will do a photo essay of this piece and will post it here on the Luger Forum.
I will also pull together the references in some of the other luger books I have on Swiss lugers about the variations in this Swiss Mauser contract. I think Costanzo might be a bit dated in his conclusions about the 1935 date. Bobba, Still, and some of the later German books on Swiss lugers expand on this contract and details a bit more than when Sam did his work.
I will also bring this piece to Reno and will let LF members, there, do a take down and let me know what they think. I am especially eager to have Ron Wood look it over. I will ask Jan Still, Bob Hogan, and others take a look as well...
If I make the SE NAPCA event in TN in August, I will travel with it and have some of the good NAPCA members take a look as well.
This one has three (3) Eagle/Nitro proofs as Bill Munis mentioned...one on the left side of the receiver, one on the let side of the breechblock, and the upside-down one on the front edge of the front sight block/base.
Regards,
Pete...