Friedrich Stendebach Double Rifle 8x57R - Most Innovative Award

Hello All,

I just acquired this most unique German Double rifle in 8x57R cal. My father passed away last weekend and left me a small inheritance.
He was a German immigrant, and very special to me. I wanted to buy something special that would always remind me of him. This is it.

Now, as with most new acquisitions, I'm trying to discover all the "tid-bits" of information about this rifle. Information from the previous
owner and research on the internet has unveiled some very interesting facts, but I'm sure that there may be someone who can fill in
additional information that would be of interest to this forum's audience.

This was built by Friedrich Stendebach sometime between 1907 and 1920. I'm hoping details of the many proof marks I've pictured
might assist in narrowing this range.

Here are the Specs:

Top Pivot Snap Action Lock
Underlever Opening
Pivoting Breach
Bushed Firing Pins
8x57R caliber (.315 bore / .323 groove - measured)
23 inch barrels
Right barrel block top marked: "Stenda Werke"
Left barrel block top marked: "Abteilung Waffen, Suhl"
Both barrel sides marked: "Krupp Stahl"(logo) - "St.m.G./15gr" - "Crown N"
Both barrel bottoms marked: "KRUPP STAHL" - "R.H." - "Eagle" "Crown G" - "Diamond K"(2 ea bbl)
Left barrel bottom marked: "serial no."
Both barrel block bottoms marked - "Eagle" "Crown U" - "7,8 mm" - "57"
Action marked: "serial no."(2 places)- "Eagle" "Crown U"
Forend metal marked: "serial no."
Ghost Ring Rear Sight w/ Vertical Adjustment
Weight is 9#-10oz
14" LOP
Right Trigger is also a Set Trigger
Cocking Indicator Buttons
Safety Indicator Button
Heel Bullet Trap
Steel Butt Plate
Sling Eyes

Interestingly, the frame pivot sockets have what appear to be hardened adjustable gibbs.
You can see them in the 8th picture down showing the frame with the barrels removed.

In searching the internet I found the following patent & ad illustrations.

Also, in 2012 the former owner received this "Most Innovative Design" Award from the German Gun Collectors Association Vintagers
in Mapleville, Rhode Island.