I'm in the middle of two playfields right now myself. A gorgar (very little touch up to do) and a Playboy (a lot of touchup to do). I have another Playboy playfield with less damage, but I figured I'd go with the most damaged. That way, if I mess it up, I have a backup. And, since this is still a learning experience for me, I wanted to try it on one I wasn't too worried about first. As in the youtube video of Pindude "anything will look better than it was".
Looks like that area in the photo above may be fun to touch up in that transitioning painted area. If you come up with any tricks for that, let us know how it works. I have a Black Knight that I will be doing eventually that needs touch up in the same type of transition paint.
BTW, are you having to level any of the inserts?