Hmm, think my wife saw something similar for sale at an Ann Summers party.
I'm assuming that the shad is 6", then in that case the curlytail has to be about the same diameter as akalin big un. A friend of mine has tried on and off for a couple of years and still hasn't been able hook up a hit. He's using a size 10/0 single (barbarian jig hook from sovereign superbaits) and two trebles set up either side as stingers. One of these towards the end of the body, the other closer to the front.
I have used the smaller version of that grub with a light size 7/0 jig head, with or without a stinger depending if the pike are "having it."
Incedently Peter, I'm very interested in the way you are using a circle hook for the shad. I've tried circles once for livebaiting which is an odd situation letting the pike move off and then winding down. (don't normally live bait in the summer, was a one off experiment) Do you disengage the reel on the take and let the fish move off and then wind down?