Why not air brush 'em with the monokote paint (can't recall the name)? use frisket paper for the stencil, and work back from the flame edges with blue, to purple, to red, to orange, to yellow, fading to the white monokote. You don't need to use all the colors, but go in order with those you do, and it'll look great. Outline with a pinstripe, and clear coat. It'll also be a lot lighter than all those layers of covering.