[OG68]

The grain on the repro plastic I had bought was flat (Ames seat back panels, OPG for kick panels and armrests) and the color doesn't come close to matching so I decided to refurbish the originals. I bought SEM interior plastic paint from NPD. The color (Medium Red in my case) was a shade darker than the plastic behind the kick panels and armrests but acceptable.

Buy the SEM plastic prep and give a good cleaning before painting
I realize this isn't always an option, but if you can, refurbish the originals.

Original armrests and pads shown in photos