RE: WACO YMF
Bill, the dummy looks very good mounted in the cowl. Are you going to make the black baffles between the cylinders, like the full scale has? Of course, leave out the one between #4 & 5 to allow air to the G-26's cylinder, and probably the one at 5/6 to allow access to the choke. My engine seems to get enough air, it doesn't feel all that hot after a 15 minute flight session.
The "Flite Metal" isn't too much different from the HVAC aluminum tape, maybe not quite as soft, and the available pieces a bit wider. It still dents pretty easily, to prevent that it needs to be applied over a fairly hard underlayment (like a 'glassed surface). Shallow creases can be burnished out as long as the underlayment isn't damaged as well. I don't suppose it's any heavier than using 1/64 ply over balsa like I did, but it does have a nice effect when painted over and the paint chips, of looking like the bare metal underneath.
The ad says0.0022222 oz./sq. inch