I managed to get in touch with Steve Corley, who is the nephew of the late Bobby Ditto, the creator of this bait and many others. Here's what I learned...
These little snake-headed worms were indeed called the Ditto Verifier, named by the late Dr Loren Hill, because, "these baits will always verify if there are any bass down there or not." He had something to do with the development of the Snatrix, too, and the matter of which came first is up for argument. The Verifier was first molded in 1980.
The funky caramel/purple one was called Chocolate Motor Oil, and the back and blue was called (you guessed it), Black and Blue Laminate. He said they were available in both 3" and 11" versions if you can believe that. And it's true that Terry Scroggins owns all of the old Ditto molds and produces them mostly for himself, but does give them away on his social accounts from time to time.
Fun little fishing tackle archeology adventure. Can't wait to see how these work, once I figure out the best way to rig one up.