Stop it Roy, you're blowing my mind. Haha.

The smooth one is different than the others so may have been made by a different supplier.
Even though the first two are identical (except for the nibs), the fact one is injected molded would imply again different suppliers.

Because I don't think I've ever heard of a clay company also doing injection molding.
So we could be talking about three different chips, made by three different suppliers.
From the little I've learned of molds being sold and changing hands from one company to the next, the manufacturing process usually remains the same.

I wonder if any one has more information on the history of these molds available other than Robert's site?