I think the smearing technique could work well here, as the wear is not bad - but the planking needs to be flattened with a light sand. If you use mylar to protect your playfield, the raised areas are going to look like crap. If you clearcoat, then it will fill and flatten. Being your first attempt, I would suggest practicing on an old playfield. Do a bit more research on clear coating, as this is a very involved process.

See how you go with the magic eraser, as the playfield will significantly improve after this process.