Hi there. Again, sorry that I did not see this whole thread when you initiated it last March. It is probably too late to be useful, but in case not here is a little info from someone who has lived almost his whole life in Maine (though not in "The County" as we all call Aroostook County).
The AMC Eagle was still a popular 4WD car. Yuppies drove Volvo wagons.
Lots of folks drank the soft drink Moxie--it was still very popular back then. RC Cola, too. For beer, it was Budweiser, Pabst, Miller, Haffenreffer, Schlitz Malt Liquor (we called the quart bottles "SCUBAs"). MAYBE Ballantine or Narragansett. If imported Labatt, Molson, Moosehead, or Heineken.
There was (still is in a lot of places) a huge amount of bitterness and distrust/prejudice against "people from away", especially folks from Massachusetts and New York. They wind up being the butt of jokes
https://m.youtube.com/watch?v=Ecg_WizWicQ
B&M Baked Beans was a popular quick meal, possibly with B&M Brown Bread.
There were very few people who weren't white, but there was very little prejudice against those who weren't.
Telecommunications was land lines, CB and HAM radio.
People love their snowmobiles.
Drugs. Every town had (has) their dealer of cocaine, LSD, etc. Up there, lots of folks would have grown their own marijuana, but there was probably a dealer of that, too.
Transportation should include small airplane services, often with floatplane capabilities.
Common sayings "cunnin'" (sexy, pretty, smart); "wicked" often used before words like good, bad, big, etc., but sometimes by itself in place of Cool! or similar expressions and sprinkled about as much as folks say "like" today; "party hearty" (often misspelled as Party hardy); "Ain't that odd!" And an almost incredulous "Is that right?" (Meaning "You don't say"). "Book it!" (Hurry, speed, etc.); "Chummy" (used like Bub or Buddie to address someone who has annoyed you).
Lots of chain saws, skidded, ATVs, firearms, fishing gear, pocket/folding knives.
I hope this can still be useful. Enjoy the game!