Broll Family of Scotland

I am trying to find parents of William Broll 1785 who married Mary Wilson. I have no other details about Mary other than her name.
Their son’s name was John Broll born 1806 in Kirkcolm, Wigtownshire, Scotland and died 28 May 1864 in Mochrum, Wigtownshire, Scotland. John had two marriages – Catherine Johnstone and Mary McMeckan
Thank you in advance for any information