The only path I would consider would be to strip it, carefully clean it where you can. Be very careful. Then shoot it with clear, and scuff it with 600 grit to take any grit or dust or whatever off, do it again and build until level. Or right after firstcoat go into a restoration mode and fix things. I done see any other way. Mylar is a poor solution and only guarantees all the art is lost/removed some day when the Mylar is pulled. If you don’t have a spray set up there is a long thread-Club discussing the use of a rattle can solution for 2PAC. Kinda depends on perceived value and interest on your end in terms of is it worth the effort. But It does look super rough and likely to get worse fast with play.

side rails are almost always stapled and screwed in from this era... should not be a major issue to deal with, either very carefully cut a strip out so they lay in it or covert to screws only and bail on the staples.

The protector is a reasonable idea that may work well. I don't think anyone has ever suggested that they move much if at all, so I doubt it would be an issue in terms of future damage. Should greatly preserve the PF.