Vid, my greatest thanks for the wealth of information in this thread. I'm about to embark on my first "real" playfield restoration (not just spot painting / clearing), so this information is invaluable.
As a quick break-down of the entire process, this is how I understand it. Please correct me if I am wrong:
1. Remove mylar (if applicable) & repair/fill any physical playfield damage with epoxy wood putty or bondo. Replace inserts if desired.
2. Apply light coat of clear to seal in wood fibers and physical damage repairs and lightly sand afterward
3. Airbrush/paint touch-up and application of waterslide decals
4. Apply final coats of clear