Yes, you posted that deed on 28/10/2013, 9:09 am but no harm in repeating it. We have noted before that John Corkill/Ann Kissag's eldest son Robert married Catharine Kissack d/o Ewan - children named in wills were Cath (eldest daur) & Sarah (youngest daur) and "only son Robert" - but you said "4 ch (inc 2 sons James + Robt) before Robt senrs death".
Maughold bapts:
CORKILL James s/o Robert Corkill/ Cath Kissage Parish Church 4 Dec 1796.
Private baptism [Robert his "only son" in will.]
CORKILL Catharine Robert Corkill/ Cath Kissage Parish Church 28 Jul 1800
Private baptism
CORKILL Robert Robert Corkill/ Catharine Kissage Parish Church 1 Aug 1803
Private baptism
CORKILL Sarah Robert Corkill/ Catharine Kissage Parish Church 26 Mar 1807
Sue