http://www.family.joint.net.au/index.php?mid=1&cid=106 BRAIDWOOD, Grevilles 1872 
and
http://www.family.joint.net.au/index.php?mid=1&cid=428 REIDSDALE same Dir.
JM
I looked at my transcripts/certificates and my Patrick was a Farmer labour in 1886 at Six Mile Flat and a Farmer by 1891 at Brushy Hill.
I did find Patrick Barrett on trove buying land with William McCaffrey in 1882 at Six Mile flat. It is him as 4 year later his usual residence on his marriage record is Six Mile Flat.
I had a look on the Monaro pioneers website and they have a Patrick Barrett born 1864 to Ellen Comans and Patrick Barrett.
They also have the Elizabeth Griggs as Patrick's wife. I just can't confirm it yet as it disagrees with my death certificate.
My Death certificate for Patrick in 1919 said His Father was Robert Barrett A grazier and Mary Green as Patrick's Mother.
I will try the Braidwood parish records as you suggested next week to try and get the parents of the marriage register.
Thanks to all I really appreciate the help given to me on this thread.
Kind regards
Tom