Among all these listed as 1977-1979, maybe many are actually R 80/7 then?
What should we do with these? Change them to 1982 by default or keep the year and change to the other model? (maybe safer)

Also, some are from series started in the end of 70s, but in episode just at the right time for being brand new when filmed. Maybe these are rather older model too.
This one for sure would be R 80/7 then:
https://www.imcdb.org/vehicle_1381699-BMW-R-80-RT.html