1966 British penny mule with Jersey obverse
In the 1960s the Royal Mint was striking coins for many overseas countries; not just Great Britain and its Crown Dependencies. In 1966 many British pennies were struck in the lead-up to decimalisation, and a comparatively small number of Jersey 1/12th of a shilling were also struck. There was apparently a mix-up during production of the coins as a small number of 1966 British pennies were struck with the obverse for a Jersey 1/12th of a shilling.
Just two examples of mule are known: one was sold as lot 124 in the Colin Cooke auction of The James Workman Superior Collection of Pennies Part 2 in November 2010 but no provenance was given. The other example has not been sighted in a sale in recent times.