Hello Frances, I knew I should have checked your CD sooner,
Here are some Corkill Deeds - that might help us sort out the 2 Williams.
Old Mau **** 27 Wm Corkill James Corkill
NSS May 1738 57 Wm Corkill Wm + John Corkill exchange
NSS May 1741 47 Wm Corkill James Corkill exchange
NSS Oct 1752 40 Wm Corkill Wm Christian
Your CD is invaluable for research in the Isle of Man, especially in tracing back after the 1841 Census.
Averil