FWIW...I've used some Rustoleum and other big-box and hardware-store paints and some no-name el cheapo bargain-store rattlecans for model work, usually for things like engines or particularly bilious colors that you might have seen on a '50s Earl Scheib job, with just fine results, but never ever ever ever without shaking the jello out of them, and testing prior to committing to use.
But the reason I'm such a repetitive advocate of testing is because I've had some real disasters, where hours and hours of work were spoiled by using an untested product that was "supposed" to be OK for what I wanted to do.