I've watched your discussion and resisted commenting until now. I have visited Norfolk Island in the Pacific Ocean, and part of New South Wales, a number of times, and as you know, most of the residents are from the Bounty mutiny crew, many of whom were from IOM. Looking at the telephone book is amazing as not only do they have regular alphabetical listings, but have listings in surname groupings with nicknames as Given names. e.g. truck, diesel, pumpa, flipper, ett.
I wonder if this was a way of differentiating between people of the same surname and given name? I'll leave it with you.

Lorraine Daly.