Well, I have the 4" fiberglass bottom section of the Apogee/Madcow Level 2 kit and fins, as they replaced the off centered fin slots section and the fins which were different lengths. I could get another MM tube and centering rings, cut down the tube, and just need to find a nose cone like Polecat used originally and come really close to the fiberglass version of the original kit. That's going to be my initial plan, or make new fins and use the bottom section for making a Public Enemy Fat Boy (the orange one), or a combination of the two which would be the easiest by using the Nike Smoke style fins that came with the Level 2 kit and make it a little longer than the Polecat Goblin so that there's almost no modifications needing to be done to the bottom section I already have. The bottom section I have looks almost exactly like the Fat Boy bottom tube.Sorry, responded too quickly. It does look pretty similar to the Goblin. I'll bet madcow parts would work pretty well.
Thanks for taking that picture of all 4 sizes for us, I appreciate it.