This is the Eric who was so good to me as a boy. I visited him in London at least twice and we exchanged some letters in French. I remember his club as making the most God-awful gin and tonic, with only a smell of tonic, and the dinner was mediocre. However, he was as kind as could be. He was the one who originally sent me a the copy of the Burke entry on the Grahams of Edmond Castle 
. I still have that copy. He had a lot of family heirlooms; paintings, letters, a huge amethyst. He died when we were in Ann Arbor, so around 1996 or so, leaving us, and each of my siblings, a pile of cash.
My sister Catherine is famous in family history because of Uncle Eric. When we visited them en masse, in London when I was about 10 (1972 or so), Catherine and the other two youngest children were given tea and cakes at a separate table. Catherine farted loudly, all the children collapsed in giggles, and Mum and Dad were highly embarrassed. Farting is something a young lady shouldn’t do, but I guess Cathy didn’t know that. I’m quite sure she still doesn’t.
Eric and Sylvie had no children.
I found his middle name on the conveyancing deeds for the sale of Edmond Castle.
In The Record of Old Westminsters, 1927, Vol. 1, it mentions Eric Charles Graham as being the brother of Herbert Henry Cecil Graham. Born 16 Nov., 1903. Admitted 2 May 1917, left Dec., 1918. So that gives his date of birth.
His date of death comes from FreeBMD records as 1996.
The story of why he inherited the estate is very interesting, and my interpretation of it is given in the details of his father. Apparently, Eric’s siblings were all illegitimate when they were born, and his parents married just before Eric’s birth.