Hi Brenda,
I have been hunting down Morrisons today looking for a William Morrison b. 1758 & discovered your information.
I already have an interest in the Callows from my Fathers side of the family & the Morrisons I am interested in are from my Mothers side.
I think William Morrison(b.1758) is the brother of your John Morrison (1760) both sons of Thos Morrison & Elizabeth Callow.
Regards
Pam