i stumbled onto a very similar sauer last spring at a local gunshow....seller was walking it around, and about to leave. we talked for a few minutes, but he had no practical knowledge of the gun, having recently bought it from the widow of a wwII veteran who had brought it back from germany (?). configuration of my gun appears identical to larry's....but mine is much earlier....#69,747 (?) which would indicate 1898 production.
weight, 6lb 4oz, chokes are .012 & .022, with bores marked 16/1....and measures to be in proof, but the barrels are lightly pitted in the forcing cones. gun is also a bit off the face....but otherwise in surprising condition, showing little evidence of use. it has the second crown stamping, as well as the wildman on the projecting lump, but it is set in a silver oval. what is most interesting is the fact it was built as a two barrel set....and the 16x16 barrels are the second number. based on what i can find, i suspect the first numbered barrels would have likely been 16x43mauser....sadly, of course, they are long gone. i believe it to be a modell nr. 4, due to second barrel set.
i intend to visit phillip crenwelge in the near future and see what he can do with it, it would be a lovely shooter.