Dear Benjamin,
Perhaps you'd like to mention this factoid in your ongoing conversation with tinfoil-hat JFKA conspiracy theorist Robert Morrow at the so-called JFK Assassination Debate -- Education Forum:
In his 1992 book, The Man Who Knew Too Much, Richard Russell says CIA Counterintelligence analyst Clare Edward Petty determined, by reading some WW II VENONA decrypts in the early 1970s, that George DeMohrenschild was very probably a long-term KGB "illegal."
Specifically, the decrypts said that a certain "illegal"
1) Was born in Poland (GdM was born 300 miles away in Mazyr, Belarus)
2) Emigrated to the U.S. before WW II (George and his brother, Dmitry, emigrated to the U.S. in 1938)
3) Lived in Mexico during WW II (GdM and his girlfriend, Lillia Larin, lived in Mexico in for several months in 1942)
4) Was a real wheeler-dealer (GdM was an insurance salesman, a speculator in oil and sugar, a film producer, a marketer of his own artwork, etc.)
-- Tom