Pete and Larry, I should let this go, but I thought I might chime in on this anyway. If you go to
http://www.makelure.com/Lures.cfm you will see the photos on makelure.com.
The first two photos you come to by Donald H. are my attempt at a aaaaaaaaaaaa hybrid Mr. Wiggly. It is a 4 inch soft plastic bait built like the Mr. Wiggly except that I have put some thinned or reduced cross sections in it to function as joints, and I added weight to the bottom front just like you mention.
What I have discovered is that in this bait size, 5 grams is all I could fit into the bait. It cast very well, it swims like a real dream, but it would be very hard to fish at 30'. Perhaps there is a way, but at this point in time, I believe Larry has suggested the only viable option to get the lure down to 30' without trolling.
OK, I should back up a little. I do fish mine as deep as 30', but I cast it out and have to let it sink for some time. Once it as go to the depth, the retrieve starts to bring it shallow. If I retrieve and pause, retrieve and pause, it works great, but it sinks way too slow to be a "jigging" type of bait.