Filming dates (Tisa Farrow related)

According to Variety Magazine, this film was in production as early as June or July 1980.

http://www.varietyultimate.com/search/?search=Hunter+of+the+Apocalypse +Warbeck&startYear=1979&endYear=1980

During the Spring of that year, from April-May, according to the Italian version of Wikipedia, Tisa Farrow filmed her role as Julie in Anthropophagus. In short, her role as Jane Foster in this film was her final project, not Anthropophagus, which she had already finished shooting. This was hard to find out, because both films were released on the same day.