...At this point I am quite confident 1983 is the most likely date of manufacture. However, I am still unsure about the model: Pacifica or Pathfiinder A-D?
According to this shared BF, the '83 Pacifica had Puch's 2600 Chromoly tubing (not the Puch blend manganese tubing). Also, a lot of the components on your bike align more with what a Pathfinder would have been spec'ed with from the factory (I had a Austro-Daimler (Austria made) Pathfinder A-D, bitd).
Road Test/Bike Review (1983) Four Enthusiast Bikes for < $300