Here's an interesting machine currently listed on feebay (starting at a whopping $1200 or offer).
It represents the basic Puritan baby bell design that spawned a whole lot of variations and may be one of the earliest models introduced by Sanders.
Unfortunately, the seller doesn't know trade stimulators and misidentified it by just lifting a description/name from a different model in one of Bueschel's books.
I contacted seller, but he's apparently not interested in comments on his listing (after all, he has a book on trade stimulators).
With the crazy starting bid, I doubt if seller would accept a reasonable offer, but may be worth a try.