I too would like much of this information. I have recently received this info which I have not yet investigated:
Patrick Cowin (bapt 6.6.1755 buried 5.06.1827) and Alice Clague who were married 7.12.1776 in Braddan had 9 surviving children incl Thomas bapt 8.04.1781 (Braddan) who married (26.01.1806) Margt Karran.
Details of their children, incl your John Cowin and my Phillip, you should have.
I note that Baptisms in Lonan New Church has a “Patrick Cowin, son of Thomas Cowin, on 6 May? 1755”. Does this take the line back one more generation?? The Thomas given name has certainly been well used in more recent years.
Hope this helps, Ross