No, not solved yet.
Plenty of random guesses, but guesses only complicate rather than simplify the mystery.
I've been going through film, by film, of the numerous possibilities, looking for the chick on the poster screaming. The poster is way too cheap to have bothered hiring a model...it's way too cheap not to be a poorly duplicated still from the movie.
Going to take forever to sift through all relevant movies... would love for anyone to help... the only way to start classifying this as a lost original film is to rule out that it's a retitling.