Ah yes, Dad confirms that his grandfather was indeed Edwin. I see that the family lived in Millbrook Rd in the 1891 census, when the mother was still alive, and in Bevois Valley in the 1911 census, but can't find them in 1901, which is strange. I don't know anything about Mary Oram's link to the family, I will ask Dad when I see him if he knows of her (he is hard of hearing, so phone calls are difficult). If there's anything you'd like me to ask my father, fire away!
Unfortunately, the last of Dad's uncles and aunts died a few years back, so Dad's is now the elder living generation of our Mabey descendants (Dad's surname is Nineham, if that is any interest to you, his Mum, Maud Mabey, married Bert Nineham, who ran a wet fish shop in Shirley High Street) Any photos would be brilliant, thanks.