28a is a bit hmm I thought. I think it goes 'Great' is high as a person might be described (minus a letter), American is the usual 2 letters and 'author's' is 'me, the author has'.
Not sure about the parsing of the first bit of 32 but the sailors distance seems straightforward. (It's 2,6). I suspect the island is a 4 letter Scottish one shortened and second letter extra ending up with 2 letters.