This is from the G.B. ad. I read it over and over and I don't see where the seller says that the G.T. rifle was the one the vet carried in combat.
" The rifle was purchased directly from the original vet whom a very astute collector (he passed away in 2006) spotted in a July, 31, 1990 local newspaper article. The veteran was pictured holding the "Gas Trap" talking about his service during WWII. In the newspaper article the vet states “he still owns the M1rifle issued in Panama to replace the broomstick rifle used in training”. The collector subsequently found the veterans name in the local phone book and called him. He later purchased the rifle directly from him after becoming friends"
I think the key is "The veteran was pictured holding the "Gas Trap" talking about his service during WWII." and that “he still owns the M1 rifle issued in Panama to replace the broomstick rifle used in training”. No place does it state or imply that the Gas Trap rifle and the M1 rifle he was issued in Panama and still owns, are one in the same.
I am sure the seller knows that he doesn't have to tell a story to sell that rifle. I think he just wanted to share the vets story.