It has been noted that when an American bomber crash-landed on a base, ground crew form other bombers would rush over to grab parts and items from the soon-to-be written off bomber. I can see things like the unused parachutes "disappearing and accounted for as war loss. It was known that ground crew accumulated stashes of commonly used parts. there were lots of other things that could be "acquired" such as first aid kits, coffee thrmoses, etc.