3 46 is certainly the proof date. 10343 can not be a post-WW2 Mauser serial number, as it would date to 1905. Even if the last Digit is lost and the number is really 10343x, it would date to 1930. So it is most likely a Peterlongo number. Not only the engraving is not Mauser factory original, but the stock, especially the foreend, seems to be reworked from the Mauser B pattern w.Roell adhered to. It seems to have been slimmed down, the "Schnabel" tip more pronounced, and checkered as an afterthought. The Röll assembled rifle, or the brreled and proofed action and preshaped stock, may well have been brought by a French officer to Peterlongo,s shop,then run by Herbert Mahrholdt, for customisation and assembly. Remember, both Oberndorf a.N. and Innsbruck were in the French occupation Zone in 1946.