I have seen at least four Airstreams that have been painted. While I chose to have my Overlander polished/Plasticoated; I had an estimate from a quality bodyshop for a professional repaint that would have been within $250 of the final cost of my polish/Plasticoat. The one advantage that you have in having an Airstream painted over an Argosy is that you don't have to deal with the galvanized steel endcaps. Since the entire coach is aluminum, it is a question of using the preparation and paint system designed for aluminum. I have heard good reports about the painting processes used by both CanAm and Inland RV.
Kevin D. Allen
WBCCI (Lifetime Member)/VAC/Free Wheelers #6359
1964 Overlander International/1999 GMC K2500 Suburban (7400 VORTEC/4.11 Differentials)
1978 Argosy Minuet 6.0 Metre/1975 Cadillac Eldorado Convertible (8.2 Liter V8/2.70 Final Drive)