New exhibition opens the ‘file cabinet’ of the late actor’s mind, spotlighting self-made collages and iconic men’s suits

• ‘A photographer with a cool and deadly eye’: Diane Keaton’s creativity behind the lens

On a recent Friday afternoon, I stood before “the wall”: a sprawling collage created by Diane Keaton. The late actor pinned objects of fascination to this collage – including snaps of herself in Parisian photo booths, a fake ear with acupuncture points, mugshots of Victorian women, bingo cards, a menu from a defunct California gambling den and a photograph she took of her friend Carol Kane – over many decades.

The piece is one of Keaton’s many personal effects on view at Bonhams in West Hollywood before showing in New York later this month. Anna Hicks, the head of private and iconic collections at the auction house, tells me that this sizable piece, covering nearly an entire wall, constitutes a mere slice of the 8x30ft collage Keaton kept inside her Sullivan Canyon home. Bonhams specialists found even more ephemera, such as signed photos of her The Godfather co-star Al Pacino, tucked underneath this towering assemblage. “I think it tells you a lot about her,” Hicks says. “All her thoughts and different things that she found important or interesting, she just pinned up here.”