I honestly don't know of any body restoration schools. Autobody tech. is crash repair, they don't teach how to restor a classic, only how to repair sheetmetal and unibody's and frames from a crash. Most people who take these courses just apply the crashed sheet metal reapir to older sheetmetal restoration. Once you learn the basics of sheet metal repair and working you can apply it to anything.
There are very few shops that only do customs and restorations because to stay in business you need to have the income from crash repairs on newer cars.