A local dealership here, Harper Motors (GM), has a 1977 GP w/3600 miles. I have looked at it and it appears to be legit. It is tan w/white vinyl roof, tan velour bucket seat interior and Rallye II's. He is asking 45k,he bought it at the Dallas Mecum auction for 35k this summer. Minden, LA
https://www.harperminden.com/searchu...px?st=Year+asc
https://www.mecum.com/lots/DA0922-54...grand-prix-sj/
Good luck,
James Q