Sadly no in terms of anything additional.
On a plus note, a massive thank you to Debra for posting the link on the Forces Forum from someone looking for their grandfather's history.
I contacted the poster yesterday through various means at my disposal

and managed to get in contact with her grandfather, Ernest MARKERSON. Ernest is Gordon's brother who, from information he gave me, struck too many coincidences for my liking. See what you make of this:
Ernest is the son of Gordon Roland MARKERSON and Phyllis Emily OAKLEY.
His father joined the army and left his mother when Ernest was 10 years old.
He recalls his G/father being called George and being a horse breeder (of sorts), which would tie in with the 'Colt Breaker' on Gordon & Phyllis' wedding cert.
He knows Gordon left and moved to Leeds where he had a family, but the last he heard of Gordon was when he returned to Ernest and his wife's wedding in 1956.
He never heard from him after this.