Okay, took the plunge and followed (I think) the Repaint Toot on a "Base Texture" for the Stone Air "Flipper".
Using Paint Shop Pro (Photo X2), I repained the texture with a green fusalage and blue wings. At first, I was really pleased. It came out all nice and shiny and chromed looking (even though I wasn't particularly aiming at chromed). The catch is that under low light, like dusk or dawn (before it gets too light), and at night, the skin turns invisable. I noticed that the canopy did that before, but didn't think anything of it (I passed it off as some "nice touch, polarizing effect", even if it's unintentional). It's almost excevily chrome, however.
I did a repaint again in an old graphics program (iPhoto+) I got bundled with a scanner in the late 90's (that works perfectly fine in Vista, thank you!), and even though it worked (Texture remains visible at low light) but has completely lost all reflectivity. It's completly "anti-glare" flat.
Alpha channel? Or is it something I adjust in Paint, or do I do some sort of processing through DXTBMP?