I'd play the heck out of it and let the next generation worry about it.

So long as the inserts are not raised or sunken and affecting the ball, keep it waxed, always use good new shiny balls (replace them at first signs of wear) and like Odin said, play the heck out of it. Take care of it if you ever decide to restore it. Otherwise forget about it and enjoy playing. Not every game needs to be a museum piece.

If it bothers you, then you could buy acrylic paint (small squeeze bottles) from a place like Hobby Lobby. They are less than $1 per bottle. Find the nearest color, and use a toothpick to fill them in with paint. I've done this with several games. Thin the paint with a drop of something called Flow-Aid, I think its called. Then wax regularly.

Not dangerous. But it will probably pull up more of what's left when you remove it.

Your play field won't show much more signs of age if you just clean it and then wax it with a product like Blitz One Grand.

with those decals - I would check who made them as there is one US guy on ebay (Classic Arcades) that is planetary pinball approved but his decals are crap - art does not line up

there is also a light weight mylar

my playfield has been like that for years and hardly got any worse, wax and enjoy the game

Yep use Blitz One Grand, you’ll love it.

If it is a keeper then I would touch them up with some acrylic paints and then seal them with pieces of mylar. Most the wear areas look to be solid colours with no gradients so shouldn't be too difficult.

As swinks said, the aftermarket decals from that seller don't fit properly and you would just be wasting your money as I found out the hard way.

For wax, Meguiars Gold Class carnauba paste wax in the metal tin and applied with foam pad.