BBC Antiques Roadshow expert forced to U-turn after offering to BUY guest's item: 'Not allowed!'

Antiques Roadshow expert Marc Allum had to retract his rare offer for a guest's heirloom after he estimated it to be worth a four-figure sum. On this Sunday's edition, experts pawed over extraordinary Battle of Britain memorabilia, an ingenious picture book and a collection of retro trainers.Allum was left stunned when appraising an original promotional booklet for the 1927 German dystopian science fiction film, Metropolis. “It’s an absolute wonder,” the expert enthused before adding:..