How exciting to hear from a cousin! Although my research is still in process, I have a lot of information on the Manice family that I'd be happy to share with you. I've seen Anthony's death record in the vital records at Groton CT Town Hall, which says he was born in St. Michaels. Also, I've found crew listings for a number of whaling voyages he took, all of which list his birthplace as St. Michaels.
Which of William Henry's children are you descended from?
I'd love to compare notes with you. If you'd like to correspond directly, my e-mail address is firstname.lastname@example.org. I hope to hear from you soon!