Playfield restoration and clear coat isn't a skill easly developed. Before you send your playfield out for work you better know what skill your restorer has.
Very few people can actually repair and touch up playfields. Watch out for the "air brushers". That skill is very limited and requires the whole area to be repainted. Air brushers have a difficult time with art work on the playfield.
One company out there has scan/decals and they "patch" your playfield. Many cases that's about all you can do. I'll be loading the pics soon.
The best thing you can do is talk to people that have actually had work done. Before and after pictures are very helpful.