I have seen what it takes. First, you need a set of headrests. Periodically they show up on ebay. Then you need a set of rails, they mount internally inside the seat. Then, the grommets for the top of the seat. There were some german suppliers selling the rails a while ago...best to keep a lookout for the parts. Of course, once you have the seat open, may as well change the pads, repair the springs...
I believe the taillamp switch is in its entirety; it was for mine. The all red get good $$$ if they are in nice shape, more than replacements