Dear Joan,
Thank you so much for this "gem". Like all the best enlightenments, it raises as many questions as it resolves! I had understood that Thomas was an iron merchant (born 1778, Ballaugh IoM) but a tailor would fit equally well (no pun intended). Nathaniel Caine married Hanah Rushton, daughter of a very successful woolen draper/merchant in Liverpool who may well have had business dealings with Thomas. I knew of two siblings for Nathaniel; William Sproston Caine (24 May 1803-1876) partner in his mining business, and Fanny (Frances) (1802-1894) living with him in 1861 census. I have also learned that he was born 1808 rather than 1810, so he fits in neatly between John and Mary.
Now, there appear to be several Thomas Cain(e)s born 1755 IoM so I am going to have my work cut out! Your source didn't give any clues as to where he was born, by any chance?
Many thanks again for this very welcome surprise response to an 18 month old posting on the site.
Oliver.