so I did a test today, I bought some of the Dupli-Color flat black vinyl dye and taped off my old parchment bucket seat and did a quick and dirty dye job on most of it.
I set it in the car and hung one of my new parchment panels and made a few pictures. I liked it, I am going to go with the black seats/parchment panels. OPGI having an Easter sale this weekend so I'll get a good price on some front seat covers.
Also, I was really impressed with the vinyl dye it looks and feels pretty good, flexible too. So My plan is to re-upholster the front seats with foam and black covers, dye the front seat backs and sides black, dye the headrests, and I'm even going to carefully dye the entire back seat rather than re-covering it since the rear seats in excellent shape except for the parchment being discolored there are no cracks or tears or anything.