The "BTH12" Marking
A marking which appears to be a crossed rifle and telescope with the letters B, T, and H, and the number twelve has been reported at least five times. All pistols shown here (with the possible exception of the last pistol shown - insufficient information) are built on immediate post-war (mid 1945) Mauser frames and have early style post-war Walther commercial slides and post-war barrels. All have the frame serial number transferred to the post-war slide. The meaning of this marking, who applied it, and when are not known.
Pistol number 118568 is one of two reported so far that is not serialized in the same manner as a standard French occupied Mauser produced pistol (i.e. up to 4 numbers and a letter such as 1234h). It has a six digit number hand stamped on the frame, slide, and barrel. A very light Mauser acceptance marking can be seen next to the right of the frame serial number. It appears that this pistol was also a 'g' block Mauser, as the remains of the original serial number are still visible. This pistol has post-war grips. The slide is not dated.
Pistol number 951g has a "BH" marking on the frame, indicating post-war use by the Austrian military (Bundesheer). This pistol has the date "1/67" on the right hand side of the slide and has post-war grips. Thanks to Rob for the report.
Pistol number 1405g is similar to 951g above, except it has wartime grips. It also has a slide date of 1/67. Thanks to Randy for the pictures and report.
Pistol number 72xxh was reported in August of 2013. It has a Mauser frame with the "clover leaf stamp" under the left grip, a postwar slide dated 1/67, a post-war barrel, and a Spreewerk locking block. The "BH" frame marking indicates service with the Austrian military. Thanks to Caza for the pictures and the report.
This pistol is up for a September 13th, 2013 at a large auction house. Little useful information was given. It is impossible to tell with any certainty if there was an old frame serial number that was removed and then re-stamped, or if the frame had no serial number to begin with.
Please e-mail me if you have seen any more pistols with this marking.