Jean Gleaves, the President of the Gleaves Family Association forwarded your post to me.
I think I can help you here.
My database does not contain your ggrandfather Douglas but I do have info on Henry Peter Gleaves and his wife Sarah (I have the middle name as Margaret) Pugh.
I will send a series of emails later this morning with material from a paper I wrote several years ago.
Here's your family line:
Henry Peter 1864-1910 was the son of, Thomas Wood Gleaves, 1823-1892 who was the son of, James Robertson Gleaves, 1799-1865 who was the son of, Thomas Gleaves 1771-1849 who was the son of, William Gleaves 1748-1820 who was the son of, Matthew Gleaves about 1725- about 1760
I will be sending the details in several emails as a single file would be too large for yahoo account to handle.