A photograph of Kirkstall Forge Home Guard shows the World War Two volunteer unit, which defended and patrolled the factory – a hugely important wartime production site that manufactured parts for military vehicles.
The inventory project also uncovered a selection of corporate Christmas cards and calendars printed in the 1950s.
The cards would once have been sold to business owners in Leeds to send to their clients and employees.
The project also unveiled a series of steel signs advertising vintage businesses, made by Charles Lightowler, a family firm established in Hunslet in 1891.
Lightowler became known for printing tinned food, sweet and tobacco containers, a selection of which held in the museum show tiny kittens driving toy cranes and sitting in cups, and a woman cuddling up to a golden labrador.
Dating back to the 1600s, the site of Leeds Industrial Museum was once one of the world’s largest woollen mills.