I did not use SEM on the seat. I will post up the product that I did use. I have a high level of confidence in it, and would most def. use it on a door panel without hesitation. As to the seat, I got the silver dye for my carpet. It is also good for leather and vinyl. So I tried a shot on the original seat that was under the back cover. Pretty much untouched and not faded. It matched perfect hence the reason why I went with that product. Im not really worried about the final appearance too much as these are just temp. Im hoping to get new covers by the end of the summer (just in time for Hershey I hope

). I figured these would look better than the worn out black hobnail that I had. I was really planning on just using the black seats until I found these used seat covers on the shelf. Looking closely at them they werent that bad, just badly discoloured so I figured what the heck.
As far as durability, I would think that they would not last being 'spray painted'. But, When I restored my '77 I bought a set of seats at Carlisle. I only needed the frames but they had pretty nice base model black covers on them. I threw them around for a few months until I was ready to re-do them. Only upon taking them apart did I realize they were camel tan and not black

Whatever they were dyed with held up extremely well. There was no wear or anything to the finish. Kinda sold me on the re-dye process.