My sources have lead me to believe that Thomas Cain was born in German in 1804. Therefore the Thomas Cain buried at Marown in 1870 would be about 8 years too old to be Christiana's husband.
If only I could get hold of the monumental inscriptions myself to have a good thorough browse through. Not just for Marown. but for Malew and Braddan too (and for Laxey for the Hulme branch of my family post 1917).