According to the post below
"Presidential firearms appear in other parts of the country, too. Harry S. Truman was an avid hunter, shooter and firearms collector, but one firearm held a sweet spot in his heart. It was a London-made guild gun, a percussion 12-gauge side-by-side passed down from his father John Truman. According to Mr. Truman's cousin, Fred, Truman's dad fell from his horse onto the shotgun and thereby damaged the hammer. The shotgun is marked by George Goulcher; Goulcher was an ex-Pat Brit living in New York who made components used by gunsmiths unable to create their own parts."

https://www.outdoorlife.com/all-presidents-guns/

USAF RET 1971-95 [Linked Image from jpgbox.com]