Send lawyers, guns and money

Does anyone know the origin of the phrase, "Send lawyers, guns and money?" Most of my searches end in Zevon, which was one of two very important additions to "Excitable Boy," but I have a feeling that that is not the birthplace.

All indications are that Warren Zevon made it up for his 1977 song (released in 1978). There's a Wikipedia article on Zevon and another about the song itself. Both articles give examples of the song's use in movies and TV shows, but neither indicates that he was not the originator. In fact in the song article, a post-1978 scholarly book (hardcover $105.95) on international economic relations credits Zevon for this phrase in the footnotes.