Have him give you references to actually see some of his work , and talk to the customers .
If he wont do this and actually give out his customer base , he isnt what he says .
Guys that do quality work will be all to glad to show his work !!

Thats the bad thing about a Body Shop , most are in if for fast turn around not restorations ( unless they specify Restoration in their adds ). Some are small and square footage tied up for long periods of time = no money generated . Plus if its not running and in pieces the interest isnt there either .
What you might have to do is take alot of quality photos of your project and take them to the Body Shop and ask if this is something they would care to tackle , and the final bill/estimate may be higer when done , as unseen Things /Items pop up . So dont be alarmed if this happens , an estimate is what it means an estimate, not a final BILL !

SprayTech