In regards to the marriages being the first or the second seems to be the unresolved issue.Below is what I have compiled. Have only included those who married at what would be considered at an older age than normal for the times.Please add any earlier marriages you might have.
Abercrombieage when first child born John abt 1736 first child born abt1762 = abt 26 yrs old James abt 1740 first child born abt 1776 = abt 36 yrs old* Issac abt 1748 first child born abt 1780 = abt 32 yrs old Colvil 1762 first child born abt 1791 = abt 29 yrs old
*Tony, I understand you are of the opinion that James abt 1740 was the father of James abt 1765.
I am also including the Dials Hastings 1732 first child born abt 1769 = 37 yrs old Isaac abt 1737 first child born abt 1781 = 44 yrs old Martin 1744 first child born 1782 = 38 yrs old
We are either missing a number or first marriages AND children, or for some unknown reasons these men waited longer then most to marry.