On both my old 2008 and new 2013 Allegro Bus, I use lacquer thinner to thin the Tiffin furnished touch up paint. From that, I assume it's a lacquer based paint. Of course, you'll get a flat finish if you're using the factory furnished touch up paint. A clear coat is required for the shine unless you are using a different type of paint.
2013 Tiffin Allegro Bus 43QGP
2011 Chevy Silverado 1500 Toad