However, I've just learned that there was a German DVD release under the title Bloody Marie which is (a) PAL so higher resolution and (b) a proper wide-screen recording, not (as far as I can determine) letterboxed. It's also uncut, whereas the NTSC version was cut at several points for nudity etc., and is in English as well as dubbed German and English with German subtitles.
The trouble is that it now appears to be a little rare (as far as ebay, Amazon etc. are concerned), selling for £20+. But I'm willing to bet that there are plenty of second hand copies around in Germany.
If any of my friends happen to come across a copy I would be pretty interested. It's not a film I can't live without, but I'd certainly be willing to pay a more reasonable amount for it.