Ice cream factory diagram

This would mean that it WAS mass produced and even had variants.

I would suggest an entirely different interpretation. When you are preparing an item for manufacture, you make prototypes, you try them out, you make changes, you make a few more, and so on until you get to a stage where mass-production starts. There is no particular reason to use the same colour of plastic in the injection-moulding machine each time you do this, so it's entirely possible that all we are seeing in these photographs are different versions of prototype. 

I can very easily imagine a situation where the Marketing people are badgering the Development people for something, anything, please, to put in their brochure photographs, and they are reluctantly, because it really isn't ready yet, given any of the prototypes that happens to be lying around, as long as it has a general resemblance to how the mass-release version is going to look. That's how industry works, in my experience.