Interior Paint

I'm ready to paint my plastic as part of an interior project. I've
painted a couple of pieces with Rustoleum plastic primer, and then with
the appropriate color of gloss enamel. They've turned out acceptably,
but I'm thinking that the "gloss" is a bit loud. I chose the gloss
enamel initially because I felt that it would be the most durable. A
Rustoleum satin or semi-gloss may be more cosmetically desirable.

I know that folks recommend SEM and other vinyl paints. I've also had a
recommendation for Krylon (I assume the enamel similar to Rustoleum.)
How durable is SEM? Is that what I should be using? For the pieces that
I've already painted, can I just paint over them, or do I need to strip
them somehow without trashing the plastic?


Thanks,
JKG