William Bridson (1735-1799) and Ann Cosbahan (1731-1812) certainly had a son John. IGI gives his christeneing as 15 Sep 1772 but this should be checked.
If it is of any interest, the male antecendents of William above were:
Paul Bridson 1693-1771 -Capt. of Douglas
John Bridson (3) 1644?-1716 MHK?
John Bridson (2) -1665 (predeceased his father) John Bridson (1) -1666

John (1) is probably the same man as John Brydsonn listed in the 1611 & 1612 Abbey Rent Rolls. I can trace him to c1619.

The Bridsons of Oristal in Malew (aka Aristle, Aristal, Eristal and today Orrisdale) can be traced by rent and rent roll to 1540.

Michael Bridson