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These were two binnacle compasses from the destroyer HMS Petard. The ship attacked a U-boat in October 1942 and before the submarine sank, two of the destroyer’s crew retrieved its naval code books for use with the Enigma machine.

Passed on to the code-breakers at Bletchley Park the documents advanced their work in deciphering German orders which some say shortened the war by a year. When HMS Petard was broken at Bowness in Scotland, the compasses were rescued by the vendor.

Two specialist dealers from the South West of England contested both lots with the ship’s main brass binnacle compass realising £500 and a second example fetching £750.

But it was a beautifully crafted British submarine brass and mahogany binnacle compass consigned from the same source that was the most sought after piece of navigational equipment when it took £1050.

The most expensive entry of the whole 500-lot mixed sale was a less esoteric item – a 20th century reproduction walnut breakfront bookcase cabinet which made £3000.