If you just unscrew those (shouldn't be hard at all, if you have the right screwdriver), and push the tiny "button" that locks the crown in place - voila, you're all set to remove the movement/dial from the case. You just lift it out.
It's a very easy operation to remove dust from the dial - just make sure you don't get any dust in the case while you're putting the movement/dial back in
I can relate to being anal with details, and from my experience, it's mostly luck when you stumble across an A+ specimen. Most tiny flaws, apart from misprintings and such, are fixable however.
What bothers you with the pieces you have right now? Please show some pics, and I'll try to help you if possible