BCP:

The only Lustrecoat spray I've had problems with is the white, but that's not your problem, now.

The polyurethane has limited your choices, many kinds of paint can't be applied over it due to solvent reactions. Also, sealing the fabric with nitrate dope keeps it tight due to the constant shrinkage of the nitrate.

What you need to do now is make a test panel, just an open frame, and cover it with the Koverite and seal ir as you have done the plane. You can try different paints on it to test compatability.

Next time, use nitrate.

Bill.