I found this searching the web...

June 16 1871

Married at St. Paul's Church, Stanley, Circular Head, by the Rev. H.E. Drew, on the 6th June instant, Arthur Colhoun, sixth son of the late MR. WM. COLHOUN, Brackey, County Tyrone, Ireland, to Elizabeth, eldest daughter of the late Mr. Francis Harkness, Greenock, Scotland (Cornwall Chronicle)

Hello,
I believe my father is the great great grandson of W M Colhoun. W M Colhoun's 6th son Arthur Colhoun had himself 11 children, eldest was William Edward Kyle Colhoun (Tasmania, Australia) who had 3 children, one being William Arthur. The said William Arthur of Launceston, Tasmania had two sons Peter and William John Colhoun.

Kind Regards,
Stephanie