A challenging one - Macklin (1700-1850s)

Hello, I have what appears to be a tricky one, and am relying on the super sleuths for this one. I am attempting to follow a rabbit hole as far back as possible, and have come to this current point: William J Macklin 1834 - 1922, born perhaps in Co Tyrone). His father was John W Macklin 1788 - 1865, who had another son John 1828 - 1904, and daughter Charlotte 1829 - 1906, with wife Mary Murtagh (co. Longford). Any super sleuths able to get further back from John W Macklin 1788?