I can not thank you enough for the help you have given.
It is also good to know that all the leads that I had followed, lead to the same places that you uncovered, though there were a few things you discovered that I hadn't come across.
I will contact some of the family trees to see if they can help me shed any light on the situation.
Maurice Alan Condon was born 3 years before my grandmother so could possibly be a brother???
I had another look at the marriage certificate and noticed that it was written by the Minister, so it could be possible (though slim) that deceased was written under the wrong person, Mabel's name could quite possibly be Burrett not Barrett and thirdly Morris is spelt wrong and should have been spelt Maurice.
I did find one of the things that you discovered really interesting, that both names were associated to a racecourse. I remember as a child my grandparents were very keen on the horses as well as my uncle mentioned that every time the name Bill Condon was mentioned my grandmother would instantly become alert.
Again thank you so much for your help and if I do manage to find any information on my grandmothers family I will let you know.