buckstix, I had to contemplate this a bit and had to restudy the original German proof rules of June 22, 1892. there are in fact three German stamps on your Kettner rifle: small eagle, crown/G, S in hexagon. But there are no German marks for the second or definite proof, crown/B and crown/U. The S in hexagon is the trademark of the Suhl Schilling forge which supplied most of the Suhl guntrade with barrel blanks and action forgings. The eagle represented first or preliminary proof of the rough barrels for checking material defects. Though most often found on rifle barrels, contrary to popular belief the crown/G proofmark does not stand for "gezogen" = rifled, but according to the original text for "Geschoss" = bullet. As the prescribed preliminary proof charge for barrels intended to shoot bullets was much heavier than the one for shot barrels, it was applied right at the first proof. The preliminary proof, W.W.Greener called it the "gunmaker's proof", was never mandatory, but a completed gun without was to be subjected to the higher pressure of the first on second/definite proof. So the barrels of your "Kettner" rifle were made in Suhl. Just to be sure, they were subjected to provisional proof there before being sent to Liege, Belgium to make the double rifle. The completed dr then underwent definite smokeless proof, PV mark, at the Liege proofhouse before being shipped back to Ed.Kettner. It was unnecessary to proove it again in Germany as the Belgian proof was accepted since 1894 and vice versa.