Wonder how much of this kind of thing is "out there" ?
On The Tonight Show/starring Johnny Carson, Mark Hamill said that when Star Wars became a hit in 1977, the cast was invited to the White House to meet President Carter. They gave Amy Carter one of the Stormtrooper helmets from the film.
...but based on the previous thread of the Don Post employee(s) who swear they made Stormtrooper helmets for the original trilogy, yet we have no screen evidence of a DP bucket used, I WONDER if DP helmets were purchased by LFL and given out as souvenirs for special occasions/guests.
YOU KNOW... It might explain the story(ies) of: "My uncle worked at Elstree on the original trilogy and he gave me this production used Stormtrooper helmet in 1982, I've had it in the attic since the mid 1980s, must be worth a fortune!" only to find out it's a standard DP bucket. And so over the years we have said that the person was glaringly mistaken, confused, or lying about the helmet itself or their relative that worked on the films, etc.
It could be that everything was exactly as they were told: They really DID have a relative that worked on the OT, and they really WERE given a Stormtrooper helmet that LF owned.