Original Garrett Gravity Trap pan - best way to clean?

[IdahoSpud1]

I bought a Garrett Gravity Trap gold pan in 1976. Took it along on my parents last camping trip (since I was a teenager, you know). Panned a small creek not far from Mount Rushmore, found plenty of sapphires, some were faceted and used in a ring for my wife.
Have saved the pan all of these decades, as I didn't want to part with it and today, had a look at it. Apparently, I never rinsed or "seasoned" the pan. And now, it's 50 year old plastic. What is your best advice on cleaning the top of it? I've purchased a new Garrett gold pan set in the meantime, however, it'd be cool to use the old one once again.

 

[Odanscoils]

80-120 grit sandpaper.

Wash it with a brush and dish soap first.

The scratches help it trap gold.

Last thing you want is a shiny pan.

 

[Gold Seeker 69]

Coarse to medium steel wool will also work and conform to the pan contours better than sandpaper.