My first thoughts on first hearing was that this was some sort of neo-80's, down-tempo modern music. The fact that this is 1983, 40 years ago, is mind blowing. What's even more shocking is that it's never had a CD release! This sounds like a cleaned up vinyl LP rip, so it seems the tapes don't exist and sadly, the vinyl LP is £400 on Discogs...
I discovered this in September in Lisbon. I was at a view point when the sun was setting and a guy with his pet rabbit strolled up smoking a doobie with this playing on a speaker, what a vibe it was