Things to look for to authenticate a 1971 GT-37 : Hood pins, argent grille with no PONTIAC script but mounting holes for it, sword stripe, dual exhaust cutouts in rear vallance, same as GTO, 3 speed manual (but auto and 4 speed optional) a minimum 350 2 bbl Pontiac V8, trimless Rally II wheels (rings optional).
This is a car from the Edmonton area. If I remember correctly, it's a 400/Turbo 400 car. It was a beautiful restoration. I may see it again, as it looks like I'll still be in this area for Three Hills in June.