Thanks for your posting, I cannot see any direct link. I had actually already seen your website as you mentioned it in a previous posting to someone else.
Having had a quick look at the IGI I see that John Dalgleish and Elizabeth Thomson had quite a few children:- John 1801 John 1807 Helen 1798 Jean 1800 Helen 1804
There seem to have been a few families (but not many) of Dalgleishes in the area and some are landed gentry. I suspect that the others are younger siblings, or their descendents. Ofcourse this is conjecture. The point is that very often if you identify the landed families then you can much more easily identify the others, since the wealthier and landed members of the family tended to have wills and trusts and get siblings to witness documents etc.
I do not know where Westgrange is but whilst Mary Eliza Oliphant did not marry John James Dalgleish until 1892, according to the IGI there are Dalgleishes being born at Westgrange from 1799 onwards. I have just looked in a gazetteer and it says that Bogside is 8 miles nw of Dunfermline and that Saline is 5 miles nw of Dunfermline. Dollar by road from Saline is six miles and so Bogside is three miles sw from Dollar. In the same gazetteer, it says that Muckhart is 3 miles ne from Dollar, in other words, Bogside (where Westgrange is) and Muckhart are about an hour's walk from each other.
If I find anything to connect the two families then I will let you know. I will continue to search for Dalgleishes from the Westgrange family as I suspect that they will have a family tree and know their co-latteral lines.