Don't want to hijack your thread (I'm having fun watching) but here is the general idea. Make the end of the body perfectly square. Get the cheeks as close as you can, then pare away some wood next to the tenon Now pull strips of sandpaper thru the joint holding it as snuggly as you can hold it and still pull. You can slightly tip it if you want to change the angle The bottom is kind of tricky but keep working back and forth until everything fits tight with no gaps. And its much easier to do if the f/b isn't in the way. Its good to do this before you locate your bridge since is may move the neck into the body a hair and it may shift it from side to side a tiny bit.