Hey mark,
I meant to comment on your previous post, about the side to side ballast/balls. I love it man. I've always just set the ballast higher, some baits I'll drill through the ballast and past it, then fill it in with lead. I've thought of the side to side shifting ballast you mentioned but have never tried to build one. I was actually thinking of making a track/tunnel in the shape of a smile, or upside rainbow. My theory being that you could control it with a quick burn or shift in the rod, and that it might also cause the bait to hunt higher or lower diagonally. Just haven't thought of a way to drill a 1/4 circle tunnel.
I recently came across a unique square bill that sort of reminded me of your previous post, this little guy- http://www.tacklewarehouse.com/AR_Lures_Crank_65_Shallow_Crankbait/descpage-ARC65.html
It seems to have a soft ball rolling around in it's head. It's either a rubber ball or soft tungsten & gives a unique thump instead of a knock/rattle. The walls on it are extremely thick as well and the tone is slight and deep. It also has what appears to be a screw in its face above the line tie. This crank will hunt in a unique way, in that it appears to be drunk, for lack of a better description. Where it really shines is in its deflection properties, that sucker will hit a rock and deflect as much as a foot. It's very lifelike. If you've ever had an aquarium with wood or rocks(especially wood) you'll see fish do this, as if they're trying to scratch an itch, hard. It drives the alpha fish in the aquarium crazy and he immediately keys in on said itchy fish. Why it drives em crazy, I have no idea, but it does, regardless of species.
Sorry to get off topic. Thanks for sharing that, now I want to go disect a KVD