Hi,
I have that family in my Tree and I am doing this for A Cochrane descendent in Australia so they must be related somehow. I think that Archibald and Margaret Cochrane's parents are William and Margaret Rea. I don't have a certificate for proof but the dates fit and names of children fit. I will try and make a file od what Ihave so far and email it to you and we can maybe help each other fill in some gaps.
I will try to do it tomorrow.