MoT's WDF

I've decided to revisit this Timex Viscount that's been on my workbench for 4 years. I think I've found a decent donor movement and hands. While I'm waiting for that, I'd like to clean the dial. Any tips for removing the patina between 8 and 12? I can't tell if it's oxidation, dirt, or...? Thanks!

The one tip I can offer is that most unprofessional attempts to restore dials result in less than astonishing results. Except for dusting off with a soft damp makeup brush or lightly touching with rodeco, I would advise to leave it alone.

I tried vinegar diluted in distilled water on the dial of the movement donor watch to see if it would strip the paint. It didn't, and it slightly cleaned the donor, but it didn't clean the dial in the pic above. Unfortunately the new movement didn't fit, so it's back to the bench.