I found this German website that describes hard bait making. I put the page through the Google translation filter and it reads pretty good. I hope it translates okay for you.
The interesting part starts near the bottom with step 15. It describes the effect on bait movement for weighting location, bill size/angle/shape and placement, eye loop/line placement and a bunch of other stuff and how it makes a lure dive, wobble, run straight, etc.
The translated website is here.