These days, it’s easy enough to find a rare or out-of-print title. Online booksellers have brought the elusive, the esoteric and the outright forgotten at last within reach. With bookshops closed for casual browsing over the past few months, many of us will instead have spent our spare hours hunting around on the internet for lost gems. We’ll all be familiar with the thrill of finally tracking down that scarce copy – and the sinking feeling that follows when the price hoves into view.

The American writer Helene Hanff (1916–97), well known for her book 84, Charing Cross Road (1970), put this feeling into words in the first letter she wrote in October 1949 to the London bookseller Marks & Co: ‘Your ad … says you specialize in out-of-print books. The phrase “antiquarian book-sellers” scares me somewhat, as I equate “antique” with expensive. I am a poor writer with an antiquarian taste in books.’

That was the start of a long correspondence with Frank Doel at Marks, which lasted until his death from peritonitis in December 1968. Hanff earned a living in New York writing television scripts and magazine articles, a period described in an earlier book, Underfoot in Show Business (1961). She read