You might check with the Giant Scale forum guys. I suspect a lot of them don't bother dropping by here. For a model as extreme as the GeeBee there may be other issues that require the CG be further forward than "proper" trim on a more conventional model would dictate.

When you said that Byron drilled it into the fuselage I'm reminded of the guy that wanted to sell stickers of the little white and black 4 slice "pie" symbol so many plans use for the CG indicator. The idea was you could move the CG to whereever you wanted just by moving the sticker....