oh, and i see i earlier posted some names as my candidates for Johns parents. James Crawford and Jean Christie. Unfortunately ive since ruled that out. Got better at searching Scotlands People and found a death certificate for that John Crawford.
Found out the post 1855 deaths show parents names (you can include mothers maiden name in the search) so found a John C with Jean Christie as mum, right age, passing away in Scotland well after our John C was in Australia.
Back to the drawing board on that one.