An old glass cinematic slide, unearthed at a tip will be added to the collection at the Ganmain Historical Museum.
Stewart Winrow from the Ganmain Historical Society said the slide was found, still in postage packing, in a box of other odds and ends.
It was used around World War II to promote the Red Cross and appears to have been posted to the then-secretary of the Ganmain branch.
Mr Winrow described the find as lucky and said it was unusual to find a slide in such good condition.
He said the museum already had a projector which could be used to display the slide’s image, which was intended to encourage cinema-goers to “buy some miles in the Red Cross Air Race”.