Hi Bob,
I've only run my RCV on the bench so far. I really like it. It starts easily and idles smooth. I don't expect it to be a fast bird using the RCV, but if I can do basic loops, rolls and cubans, I'll be happy. I want to fly in a more scale manner that aerobatic. I know what you mean by being sucked in by the details. The way I made the exhaust was to make one stack out of a product called Sculpt Easy modeling clay. It's a polymer clay that is easily formed. Then it is hardened by baking it at low temp for about 15 minutes. After baking it, I used epoxy/microballoons for adjusting the shape and adding the seam/weld line. Once cured, I use a product line called Alumilite to make a rubber mold and cast resin copies. The tough part was using a dremel to hollow out the stacks. I mounted them onto a strip of styrene and painted them aluminum. I then use an airbrush to paint them with several different colors. I used rust, and a couple of mixed colors that I tried to match to some color photos. One tip, make sure your original is perfect, spending time on it will save you from having to correct any errors on 12 later!

Scott