Steve -
I've been using Testors Clear and dullcoat Lacquers for years with pretty good results, until my last model. Almost ruined it. The can may have been old, whatever, so I had to buff it out, and then air brush it with MM Acryls Clear Gloss. It may not "look" as glossy as the lacquers, but the decals laid down flat! I also spary the entire model for uniformity, but go heavier on the areas that will receive the decals, and lighter on areas than won't. Apply the decals and wait a few days, and then go over it with flat. The results are quite good.
Archer out.