Originally the name was spelt Duffety. The Duffetys I am in touch with are from Bristol, UK. Apparently the Duffetys who emigrated to New Zealand and Australia 🇦🇺 began to spell it as Dufty. I researched the origin of the name about 25 at the Mitchell Library in Sydney, NSW, Australia and there discovered the name is ancient in England. It goes back to the times of knights and jousting contests. An ancestor was said to have been "doughty in the joust." Meaning he was courageous. Jousting was a dangerous enterprise so he must have been quite a man. Other spellings are many - such as, Doutty, Doughtie, Duffy. Most of the recent Duffetys, that is, during the past 200 years were coal miners in Gloucestershire. Couldn't find any noblemen or even doctors or clergymen 😳