A one-off “high chair” made for a star of the Oscar-winning film Oliver! and since used as a cat bed could be worth up to £6,000.
The chair was specially made as a joke for actor Jack Wild, who played the Artful Dodger, because of his relatively short stature.
It was brought to BBC One’s Antiques Roadshow at Wrest Park in Bedfordshire by Wild’s widow Claire Harding.
It was valued together with his original script and an album of photos.
Dealer John Foster, who said the items together could fetch £4,000-£6,000, said: “It’s so cool, you’re not going to get another one.
“In all the years I’ve been going to the Roadshow, if they said there was only one thing I was allowed to record, this would be it.”
The British production Oliver!, a musical version of Charles Dickens’s novel Oliver Twist, was released in 1968 and won six Oscars.
Ms Harding said the chair, which Wild used on set between scenes, had been made as “a bit of a joke” due to his height.
He was older, at 14, but smaller than Mark Lester, who played Oliver, so he had to have special lifts in his shoes to make him look taller in some scenes.
“There were so many jokes about his height that the chippies [carpenters] made this instead of a normal-sized chair,” she said.
Now, she said, it is “just part of the furniture” at her Hertfordshire home, with her children climbing over it and her cat sleeping there.
She was delighted at the reaction at the show’s recording.
“When they realised what it was and who it was connected to, there was such a warm response, there was a sense of love really,” she said.
“It’s not about the value of the chair. That’s the value – the fact Jack is still remembered with warmth.”
Wild lived in Toddington, and then Tebworth, in Bedfordshire and died of cancer in 2006, aged 53.
Sunday’s episode of the Antiques Roadshow will be available on the BBC iPlayer.