[60-66]

Heres some GMC interior and paint information from a 1965 GMC data book. Assuming your truck is not a "Custom" ? Seat would be Fawn vinyl . From past experience and current trucks , the GMC seat belts in my 66s are black with a GMC logo in the buckle. Ive never had a 65 GMC with belts , but the literature for GMC points to the belts being black with a plain buckle , Chevy accessory belts for 63-65 are also black. Fawn belts were only used in 1966 Chevy. They had smooth buckles , in 1967 Chevy, same belt but with a bowtie on the buckle.