John,
Do you have a Norvel tank?
If not, you might look for one of those to try on your AP .061. That would add some nose weight, while moving the engine forward, and shifting the CG forward as well.
They made two sizes of the Norvel tank if I'm not mistaken, and the larger would probably be longer as well.
Other than that, it should be pretty simple to extend the nose and beam mounts, to get closer to the proper balance.
Bill