RE: McCoy redhead stunt engines
We were just flying sport, stunt, scale and early (heavy) combat types with normal K&B, Fox, O&R, McCoy and whatever. None of us had a Dooling.
Profiles were popular because they were cheap to buy and didn't take long to build.
Later on I did come up with a couple of McCoy .29 redhead RRV and .19RRV engines but they weren't something we normally flew.
The Powermist worked fine for our models. Most of the fuels had N/B if I remember correctly. It would eliminate high RPM "Crackle." I always loved the smell of glo-fuel in the morning.