Can you paint over a clear gloss finish?

Yes, you can spray over a clear gloss. Make sure its fully cured. Also, to help with the new paint adhesion, it wouldnt' hurt to scuff up the gloss surface with fine sandpaper where you are planing to re-paint.

Thanks Nathan and I also read somewhere that some gloss coats yellow where as Future finishes do not. Can you comment on this?

I've read that too. But I haven't been building long enough to find out myself. IIRC, most of the yellowing occurs with Enamel based clears(many years later..). I'd think you'd be safe with any acrylic gloss, Future included.

I have often sprayed color over Testors glosscoat with no problems.  And, while some clearcoats used to fade and yellow over time, I believe they fixed this long ago.  I have several models many years old with glosscoat or dullcoat and none have yellowed.

Thanks Don. Appreciate the info!