Hello and thanks for the welcome and for replying so quickly.
What you say is quite correct and yes his name Mullen was the one on the certificate.
To be honest, he had already contacted the Regiment as the obvious place to find out his father`s details before I got involved in trying to help him. I believe his birth certificate was not in a good condition and that and the fact that the surname that he had been using for the past 70 odd years was different, made the regiment refuse his application. He is getting on a bit in years and not terribly good at writing/filling in forms etc. and I think he had some difficulty also in taking the first step, at his age, of approaching officialdom shall we say. When he was not able to get information from them, I think he got very despondent and was ready to give up. To make matters even more difficult, I gather he had been completely estranged from his mother for many years for reasons that I will not go into, therefore he was not able to get any info from her at all.
Although I am very new to RootsChat I am not quite so new to genealogy and having had some small success with other searches, I would dearly love to be able to help him. We are at the opposite end of the country to the area in which I believe his father was born i.e. Lanarkshire, and I cannot see him travelling to Scotland to do research, though if I did manage to find some family for him I am sure he would make the effort.
Thanks again for your interest.
Best wishes,
Linda.