Wow, we are getting quite a bit of information together...Thank you very much!!!
I think there is a possibility my pistol was proofed again in the 1950 years and the original London proof was overstamped.
Please have a look at the details of the stamp on the barrel. Now I am really looking forward to the archive letter......
I just looked up
Colt 1905 Military .45 ACP Pistol British Proof Marks Lanyard - Coltautos.com
This pistol was also re-proofed in the 1950ties.....