fearn,
you are right about the sangkil head (at least the ones being used for fishing) being detachable.
bill,
I think the writer of the article, given the circumstances at that time, was not able to verify or double check the information passed on to him.
but, here's a comprehensive link on the history of the Sulu Sultanate:
http://www.seasite.niu.edu/Tagalog/M..._the_royal.htm
lutao, by the way is part of the local dialect which means "to float" - in reference to the sea-going ways of the tausugs, samals, badjaos, etc.