I rather doubt the top coat is dope. And dope might react poorly with it. I'm afraid that a quick coat of dope is not going to repair those cracks in the paint. I was simply trying to explain the possible process that the builder appears to have used to paint the plane.
I suspect the top coat is not dope. Therefore, you could 1.) try sanding everything off, and starting new. 2.) sand everthing off and then use iron on film, 3) fill in the cracks, shoot primer, sand and then repiant it. But if my assumption is correct about the builder not using Dacron or some other fabric, your paint job could easily show stress cracks also within a short time.
I would suggest that you simply fly the plane as it is now. Those cracks are hard to see at 60 mph and fifty feet away. Then maybe some day later you can give the plane a proper restoration.
