Brilliant Movie, Brilliant Move by Shameless!
One of the finest of Argento's early trilogy.
Here's an article that may be of use, and/or interest... (or at least might get me foot in the door...
as I was too late for the Cannibal Holocaust release)
CiNEZiLLA - Falling asleep to movies since 1970: Four Flies on Grey Velvet
Enjoy!