I would like to know that as well Mitch seems to have some information beyond the Mary Ferrell document. Maybe he could share the source?
It's in the document itself. In section I, Oswald is presented as a former member of the "Infantria de la Marina." Why add the Spanish translation? In section III, there is a preceding upside down question mark. You won't find it on an English-language typewriter, only a Spanish or Portuguese one, AFAIK. "September 22" is in section IV.
"To date, little else is available here on RUBENSTEIN." Where's "here?" Here seems to be relatively isolated, like a foreign country.
The document's discussion is generally very Mexico-centric.