you must post pictures. you must post pictures. There weren't (until, i think, maybe '89) inexpensive paramounts. No SLX paramounts were inexpensive bikes. I'm pretty sure that there were no Japanese SLX bikes built, either.
The parts that you describe are way,way more like early '70's parts, and the mix that you describe is nearly exactly as a lower-level European bike would have been spec'ed from that time frame...
you must post pictures...your eyes are getting heavy...you must post pictures...