OK so suppose you do nothing and now you have an airplane that is only a little off. So maybe that airplane goes through its life a little off and never seems to be all it could have been.

Consider this truism: When balancing an airplane on a conventional point balancer and the airplane is not level, forward or backwards You have now just balanced the airplane at some unknown point and not where you may carefully laid out from instructions. As it is now I suggest putting it on the balance device and move the airplane forward sufficiently to balance the airplane completely level, and measure this CG point now. You may be in for a surprise.

Always balance with the airplane level, never a scoosh down for mother and country. Do what you have to do either use ballast or move stuff. Move the battery forward, I know, I know bet its not all the way up to the engine mount/firewall or even forward in the cowling along side the engine. I have done many ships with batteries forward along side or above the engine and it has proven to be a very reliable and effective way to avoid ballast for airplane with a penchant for excessive tail heaviness.

John