Hello Mike,
Many thanks for responding. Unfortunately I've not been able so far to find Theodore Diamandis's date of death, although family believes it may have been as early as around 1920. I know he went to New York twice before the Lusitania trip (in 1904 & 1911). He came from Greece/Turkey originally and lived in London certainly as early as 1903/4, and possibly earlier. Any info. you may have about him would be most welcome.
All the best,
Gill