RE: Dynaflite Corsair build
These Corsairs are pretty light already: mine weighed 5 1/2 lbs, with the mech. rotating retracts and a Saito .50.
I like building light, but sometimes trying to lighten it up just isn't worth the effort. Case in point: lightening hole in the wing ribs would subtract but a few grams. I prefer using other menas to keep it light, such as servo selection. Back then, I used Hitec 225s, which weigh about 1 oz each, yet have same torque as standard servos. Using 4 of them reduces weight by 2 oz (assuming standard servos weigh 1 1/2 oz each).