Or... use the cradle and pendulum method to find CG.

Hang the plane form a single line, tied to a cradle. doesn't really matter how you cradle the plane as long as it hangs level.

Hang a rock or somehting from a string, tied right onto the first string which is supporting the cradle. The rock will be directly over the ACTUAL CG. (where it really is... not where its "supposed" to be.)

If the rock is off to one side... the plane is heavy to that side. If the rock is ahead of the place the plans say the CG SHOULD be... its noseheavy.