The only additional information I have obtained since posting my original message is that I have found out that my Gt Gt Grandfather( Robert Coulter's father)was a Charles COLTER ( spelt this way per Robert's marriage record). Robert's name was also spelt COLTER on this record but spelt COULTER on his death cert.
One of the witnesses to Robert's marriage was a Joseph COLTER and I would presume that he was one of Robert's brothers, but that is just a guess
The address shown on Robert marriage record is simply " SLIEVENAGH" but not sure where that is in relation to Ahoghill or Portglenone.I suppose it could simply be the name of a farm.
Can I give you my e-mail address - it's : email@example.com
I don't suppose you have any contact details for Kenneth Livingstone ?
Look forward to hearing from you and thanks again.