I think that Mr Big may have been based on certain drug dealers, as an update to the character from the novel, which of course did not concern drugs, but the smuggling of gold coins to finance Soviet operations in the United States.
So, my question remains, was Mr Big, as written by Tom Mankiewicz, based on real life drug kingpins of the early 1970s in America? If so, whom, would you say? A book I bought recently has given me a few possibles, but I'd like to hear from the good folks at BaB first of all.