Supposedly taking SAT prep courses on average moves a test taker one standard deviation to the right, and its not uncommon for even greater improvement. Seeing that when the SAT was developed for it not to be taught to I think there is plenty of hope for increasing you ASTB scores. It will take a bunch of hardwork, plus taking practice tests over and over. Good luck to you it appears you have a lot of hard work and a few standard deviations to bust through.