<i>One thing I've noticed is that a number of the spray-cans labeled "acrylic" or "lacquer" are methanol resistant but wipe almost straight off if you expose them to nitromethane. </i>

Some cheap lacquer's are a mix of acrylic and non acrylic lacquers. If you use glass cote acrylic lacquer you will be ok. If you are testing with pure nitromethane, then even Sig butyrate dope will fail that test, dope and acrylic lacquer are good to about 20% nitro. The control line stunt guys use a lot of automotive acrylic lacquers, fills faster, and dries quicker than dope. They do use the aluminum based silver dope for a filler. I think they spray about three coats of silver and sand most of it off then three more coats till they can sand with no pores showing and no bare spots. This is much lighter than primer as aluminum powder is very light. Then they top coat with acrylic lacquer auto paint, then acrylic lacquer clear. All of this work on top of silkspan no less.