D. V. G. de Pass was b. 1949, was a solicitor, and appears to have lived at Palm Beach, Florida for some time; his mother was Marie Elizabeth E. (1914-1988), dau. of Frederick Oscar Eberhardt. I could find nothing on a marriage to 'Violet', unfortunately. His father, Lt-Cdr John Gerard Irvine de Pass (1924-1981) R.N., died at Kensington, but was buried at Mansfield, Richland, Ohio, U.S.A., further suggesting some kind of American connection. Lt-Cdr de Pass's father was Gerald V. de Pass (1894-1959), a Colonel in the British Army (served with the 4th Royal Irish Dragoon Guards as a Lt, perhaps remained with them), who married Elizabeth B. B. Irvine. His father was John Jacob de Pass (1853-1922), of the London Stock Exchange, of Bayswater, who married Ada Kate de Pass [b. London], dau. of Arthur D. de Pass [b. Lynn, Norfolk] (thus presumably a close relation). J. J. de Pass was the son of David Daniel de Pass (1817-1890), a merchant born at Lynn, Norfolk, resident at Paddington, formerly Bloomsbury; given his place of birth, D. D. de Pass is presumably of the notable Sephardic Jewish family of de Pass, who were shoe manufacturers there; according to several sources, this family descends from Elias [de] Paz, among the original 'Twelve Jew Brokers' of 1697- for more details of which, see here (I certainly knew nothing whatever about this subject; I'm sure some here are better informed on this kind of thing though!)
http://www.jewishencyclopedia.com/articles/3737-brokers-jew