Don't splash out yet!
I have Manx Worthies. In the index there are six Teares, but none is an MHK, there is no Alfred and the only James was a temperance worker.
What can you tell us about your great-great-uncle? A date and place of birth and/or death perhaps? If he is a blank, what about another relative that lies between him and you, such as your great-grandparent?