Mr cox lol do not be negative dude. This thing with a 15 doing 100 mph will be fast for it size. I posted this for others to look at so since there isn't many 1/2 size planes and kits out there. You can kit bash this some to make how you like. The weight is will the electric motor, speed control and battery. the suggested set up is real close to a .074, two ounce tank and the extra servo. add another 6 ounce and you are at 24 ounces with a 15. so 24 ounces on 150 square inches is just fine.
Also I posted this for the guy that wants to fly in scale fashion with a 1/2A engine with throttle. I will shorten the gear on mine with smaller wheels and might even add some small wheel pants.

Pond the cowl is fiberglass and from the back of the firewall its 2 and 3/8 of an inch.I will remove the electric wood mount in the pictures and add a small layer of light ply on the inside to seal up the holes. For this plane I think i will use an AP 15 with and open header exhaust.