The Billingford Hutch is an oaken chest in the Parker Library at Corpus Christ College, Cambridge, which was used to store collateral for student loans in the 14th C. It has three locks, each decorated with a motif that was inexplicable to the curators until a chance visitor identified it as moonwort—an herb which according to folklore can unlock locks and unshoe horses and which also figures in alchemy. Isn't all of a rich potential for inspiring stories?
My first thought was, a magical version of the chest belongs in Polly Shulman's delicious New-York Circulating Repository, which first appears in The Grimm Legacy. My husband said, "Hogwarts!" A fan fiction episode set in either of those worlds could make for a good writing exercise. Even better, thinking about one might lead you into inventing your own magical library.
My mind leaped also to the (fictional) Boothby Lock in Ali Smith's Companion Piece. What really happened at the Parker Library suggests one of those novels built on the current investigation of an object coupled with one or more stories set in the past.
The beauty of three locks suggests a folkloric test like the one in The Merchant of Venice. Locks and keys of gold, silver, and lead perhaps? In any case, here's hoping the Billingford Hutch unlocks someone's imagination!