Ingo, it all begins with the chassis serial number off the driver's door hingepost.

Should read: 101 24 P Z _ _ _ _ _ _ or similar.

GMC offered two varieties; standard and deluxe. Deluxe option has a chrome grille bumpers and window trim, hood bird, and were usually two tone.

Parts are available with rear fenders being the hardest part to replace since they are not reproduced, but nothing is so difficult that you can't find a solution.