When Alan decided to build another radial engine, he decided to make it a show stopper. He painted each of the parts as he built them, using three separate coats of paint. I asked him about the paint, and this was what he said.
I used Tamiya Acrylic model Paint. The parts need to be well sanded and it takes three coats. Let it dry for several days and you should have no problems.
It looks like Alan color-coded the parts – an interesting concept.