Kevin,
You can apply Krylon over dope but not the other way around. Krylon original is acrylic lacquer (except for the small Short Cuts paint which is acrylic enamel and not fuel proof), heavier than dope so do light coats. If might be fuel proof for low nitro but always do a test piece. It should be allowed to gas off a couple weeks before getting exposed to fuel.
Best, DennisT