Hi Wanda. The certificate I have is for a John Bourke and Agnes Wilson. It is only a small scanned copy of the certificate and quite difficult to decifer. I think the date of marriage is 18 March 1926. John is registered as 35 years old which means he would have been born c1891 - nine years after the Sopp shooting. However the date could be 1906 or 1896? But it does say, now you mention it, John's parent were John and Catherine Bourke (cousins). I couldn't make that out until you mentioned it. The thing is, Catherine (daughter of John & Ellen) didn't have a cousin John?