There is little odd when it comes to German arms. There are examples in 261xxx that were proved in 1938 was well as 122xxx proved in 1928. After a piece of metal was issued a serial number, it could remain in stock until an order was filled.

If Kiwi's has "Sauer und Sohn" with only overhanging scears, then it is going to be the continental version of the Model 180E, which is a Model 8E.

Kind Regards,

Raimey
rse