Hey winger1955,
The measurements to figure CG are real easy to do with a tape or yardstick even. They don't have to be any more accurate than you would get with a wooden yardstick and eyeball. Then plug them into the CG estimation application at that website, and you're good to go.

Only tricky measurement on a swept wing would be the LE sweep. And with a model, just lay out the wing by itself (if it's one piece) on the floor to have room and a flat reference area. If it's two piece lay the model upside down in the yard.