Years ago I was in the DC area visiting my boyhood friend, we had dinner at his wifes parents. Turns out her father worked in the CIA, and on finding out I was a gun friendly type, invites me to the basement. He had a foot locker of old guns, brought back from Europe after the first world war. His father was some type of official , and had recoverd the guns from a lake, where they had been dumped after the war to keep them from civilian hands. When the lake was drained years later, the weapons were found embedded in the mud, which was largely oxygen free. They were in pretty good shape, considering (mostly just finish wear) He had a nice 1917 colt .45 revolver, and host of oddball european pistols.