First sighted in the Heyde Sale in 1974, the 1864 Sydney Mint half sovereign featuring a Roman I in the date in place of the typical Arabic 1 is one of the scarcer errors of the series. While scarcer than the 1858 half sovereign with the incorrect legend, it has not nearly received the same attention and thus remains in a similar price range to the ordinary type for the date. It was most likely caused during the re-punching of the letters, a technique employed by the Sydney mint to extend the working life of dies with the incorrect punch being used for the 1. The MS63 example graded by PCGS (illustrated) is this variety.
