ChiefK, there's flying and there's sitting on the ground.  You're on the right track for getting the flight trim closer to neutral by continuing to move the CG back until you only requre a small amount of down pressure to fly level inverted.  The first step would be to adjust that stabilizer back to mid point as what you used it for is not why it is set up this way.  If the main gear legs are mounted in grooved blocks as was very popular back then start by ensuring that any bend is to the rear.  If needed bend the gear about a half inch back or even get some music wire and bend your own legs up that has the right angle back to achieve a stable stance.

There's some good pattern model flyers that were flying a lot back in the day when the Intruder was hot stuff on the contest scene.  Hopefully a few of them will chime in about this issue.