I also have an ancestor named William Holmes. The family goes by the name of Blount. He was supposed to be on the Guerriere during the War of 1812 and jumped ship somewhere between Boston and Nantucket.
It is said he was hidden in a wood pile by the people of Nantucket when the British came looking for him. He married Eliza. Hammond in 1814 in Pawtucket, RI.
He took his mother's maiden name of Blount and henceforth was called Willian Holmes Blount. It is believed his mother was Ann Blount of England. He was baptized in Sepul Church, London. @ 1790. I have a researcher in England looking for information on the crew of the Guerriere as we write.
Eliza and William are buried in Bourne, MA
I am very interested in any information you have. Even if you do not believe my William and yours to be the same. I am not sure this story is true and I would like to compare stories.