I would agree, it is definitely 2 different James Cains.

My research and Donna Douglass's research both link a different Mathias Cain dob 1813 and dob 1840 as the son of the SAME James Cain (i.e. same exact christening date).

This matters in that If I have the "wrong" james cain, the rest of my pedigree is incorrect.

Is there any way to verify a date of birth for the james cain that married jane lewin?

I found a record of Jane Lewin Cain's will but haven't seen it - might that give more info on her husband?