Yes that's right, LBX stands for letterbox. I was just as astound and sceptic about it as all of you btw, at the moment I can't guarantee it was from '78, but I'm telling you, the guy knows what he's talking about, so my guess is he's right. One thing I do know for sure is that it was a PAL widescreen version with English audio, and it came out of a very old cover I had never seen anywhere on the internet. We did a quick search but ended up not finding it anywhere (if it's not on lddb.com that sais a LOT). As soon as I get the scans I'll post 'em here.