I strongly recommend John Drake's Flint and Silver. This is the first of a three part prequel to Treasure Island.
It's available from Amazon or check your library.
The second book Pieces of Eight has been published in England, but is not yet available here in the US. I was able to get a copy from Goldsboro Books in London, but they appear to be out. It appears to be available from Abe's Books (www.abesbooks.com ).
These books are not for children. There's quite a bit of profanity and violence with a bit of sex thrown into the mix.
But, I found them to be great reads.
Enjoy.
Sounds promisin', Mate.
I'll have to steal Borrow without permission a copy soon! ;) ;D