There are a covey of witch museums around town, including the world-class Peabody Essex Museum, which houses 552 original documents on the Salem witch trial.

BBC: Historical day trips from Boston

Mr Murrell said that as a "geeky teenager" he had regularly seen the Witch during many trips to the museum and instantly recognised its parts in the background of the photograph.

BBC: Two-tonne Witch computer gets a reboot

On subsequent trips to the storage facility the various parts of the Witch were found, retrieved and then taken to the museum at Bletchley where restoration began.

BBC: Two-tonne Witch computer gets a reboot