For choke, there has to be a "Crown" over "W" stamped on the tube. 140xxx is going to be pre-WWI. With the pre-rifling bore stamp which was supposed to have changed to mm in 1910, but of course there are exceptions, and the patent number still stamped on there, I'd guess circa 1908 but it could be later. Up until 1923(I think) German patents were for 15 years so 1893 + 15 would me the patent would expire circa 1909. There are several Sauer books and Mr. Jim Cate of Chattanooga has penned one and it is available from him or from GGCA(
http://www.germanguns.com ).
Kind Regards,
Raimey
rse
