1934/35 Centenary Florin Pattern
It is well known that a small number of Melbourne Centenary florins have a prominent nipple on the right pectoral of the horse rider. The reasons for the nipple are unknown but there is speculation that it was considered offensive and removed prior to striking the bulk of the 75,000 coins (p32, Verheyen, The Enigmatic Proof and Specimen Strikes of the 1935-35 Centenary Florin in Australian Coin and Banknote Magazine, August 2007).
The origins of the nipple are even more unclear - it has long been believed that the pattern Centenary florin in the Museum Victoria collection (https://collections.museumsvictoria.com.au/items/55697), which was sent from the Royal Mint, had a nipple. Closer inspection would suggest that this is not the case - on the Museum Victoria pattern, the nipple is triangular in shape and is centred above and to the right of where the true nipple should be. The nipple on the pattern is likely damage to the die - the pattern Centenary florin shows many examples of die damage, including spots in front of the R in FLORIN; above the horse's back left hoof and in the horse's groin, all on the reverse, and in front of the G in GEORGE; above the V and above the second E in EMPEROR on the obverse. There is also a second pattern struck in London, currently in an institutional collection in the United Kingdom, that has no nipple, or any of the other damage spots on the reverse (p230, Briggs, Australian Florins 1909 - 1963, 2019).
A possible explanation is that the pattern (struck with damaged dies) was sent to Australia and approved, then when dies arrived in Melbourne a nipple was added as it was thought that the nipple-like feature was part of the design, and then the nipple was subsequently removed to moderate the rider's nudity. Whatever the true series of events, the nipple on the London pattern differs quite obviously from the nipple on the Melbourne specimens.