This took some doing. My stock Monogram 1/12 scale 57 Chevy plastic model kit came with the option of solid molded bench or bucket seats. I was going to go with the buckets, but thought, What about modifying the bench seat to actually operate like the real car? Remember having to fold the seat forward to get into the back seat of a two-door? Well, after many hours of cutting, gluing, and trying different ways to hinge the seat backs so the outer edge of the seat back folds farther forward than the inner edge, I finally made it work, however imperfectly.
The hinge arms are nylon model airplane micro pivot hinges and flattened brass tubing. the ribbed nylon hinge plugs into piece of styrene tubing glued to the seat frame. The inner part of the seat backs pivot on a small bolt and nut thread loosely through a styrene bracket glued to the underside of the bench seat. Everything can be disassembled for putty and painting.