I'm willing to pay for a copy of this movie

This is Arne Mattsson international thriller Mannen i Skuggan from 1978. It also has the following english titles:

A Necessary Action

Black Sun

Man in the Shadows

I've been trying to find it for many years, but no luck. I don't know, but it should be released on video somewhere in the world! I'm quite sure it was shot in English, so it was never meant to be a pure Swedish movie.

So, if you know where to locate it, maybe you have a copy yourself, know where to download it... I'm desperate - Let me know!