A memorable piece of "TV history" has been stolen from England's highest pub in North Yorkshire, its owner said.
In the 1980s the Everest double glazing company demonstrated its product in an advert filmed at the Tan Hill Inn, near Richmond.
The late Ted Moult dropped a feather next to a window as a gale raged outside.
The feather was mounted in a display at the pub, but was thought to have been taken by a stag party from Leeds.
The feather was mounted next to a picture of Moult in a frame and was displayed on a wall of the pub, which stands 1,732ft above sea level.
Pub owner Tracy Daley said: "I am gutted. I would say 85% of our new customers at some point mention the advert. It's a piece of TV history.
People look at the picture and say: "I remember that."
She believed a stag party from the Leeds area which visited the pub may know about the feather's whereabouts, and she has offered a reward for its safe return.
"I would love to see it back," she said.
Moult, a farmer-turned-radio and TV personality, was remembered for the double glazing adverts.
The feather being dropped on the inside of the window was designed to show that the frames did not let any draughts in.