I used ME on my '76 Williams "Space Odyssey", and the results were fantastic.

Also just used it on a '67 Williams "Doozie", and it did a great job there too.

Just be careful as you go, that you're not pulling up much paint; once you get started it can go fast. Results are awesome though; takes those swirl marks right out.

Once you've hit the playfield with ME, though, don't wait too long before either clearcoating or waxing the playfield; if left to sit too long dirt/dust will re-settle in the cracks and the swirl marks will become visible again. When I'm working on my machines here, I cover them up with a clean beach towel between sessions; that way I don't get any excess dust or dog hair falling on the playfield.