Thanks to Trevor and Valda for your help. I'm loathe to tell you his name as I've been helped a few times in the past with this family line. Recently, I met up with a cousin through genealogy, whom I've not met for 50 years. She had a marriage cert. for this gt grandfather, and to my utter horror his father's name was James. The family I had traced had his name as John. This family I had felt a real connection to, and had travelled to London to look at their houses and take photos: I had sent for at least 6 certs and 1 will and had joined Ancestry solely to find their London baptisms and marriages. It had taken me days of trawling London church records and Ancestry- and I had shared this information with many family members especially as many baptisms and marriages of this family were conducted at St James, the church where 2 of our grandchildren were christened. The one mistake was with my gt grandfather. I'm sure the rest was correct but just not my family! Sorry to Valda and a few other RootsChatters for my incompetence and inexperience.
Anyway, back to my question: his name is Charles Webber. His army record states that he was born in Westminster, St Margarets, as does one of the censuses. He is on the 1881 census with my grandmother Ellen, so at least I know that to be right. The marriage cert. from my cousin is correct, as it give the correct name of my gt grandmother and her father whom we know was a miller. Charles' father is given as James Webber, stonemason. By his army record, he was born around 1840 and died in 1886, in Colchester.
I suspect he was either illegitimate or his mother died at his birth. He's with an old lady in Devon in the 51 census and an army recruit in the 61 census. He's never with a relative to help with the tree.
Any help appreciated, regards, Eileen