Why not build the stab & elevators out of 3/8" balsa?

You'll want the tail weight anyway!

I built the stock stab and sheeted it with 1/16" balsa, then built new elevators out of 3/8" sticks. Just do it, it's much faster and simpler than what you are describing here:

"pretty simple: build elevator stock. when all built (not covered) route out holes in the joints and inlay pieces of hardwood. (maybe some of those nice bamboo BBQ skewers. should make it nice and strong. shouldn't add too much weight either because only weight is difference between bamboo and balsa weight. what do you all think?"