I've always had a liking for Ideal's Zeroids... weird and wonderful robots for sure. So of course I'm glad to have them (and their later cousins, produced and unproduced) well accounted for in the archives in original design and technical drawing form (pencil on vellum). Above you can see original CBS design drawings for the unproduced Robo Force robot Tiltor (well, in this case, his head), which had been called in the preliminary design stages "the Bender Robot". (It appears a pre-production sample of Tiltor showed up not long ago on eBay; no we didn't get that one, but this means it's likely there are more out there to be found). (An interesting aside- I'd posted this same picture on my favorite toy robot chat group Alphadrome over 5 years ago, and recently was contacted in regard to it and Robo Force, and if I knew who owned the rights. To make a long story short, after much discussion, negotiations and ironing out details, this led to my help in facilitating the sale of the rights along with a few other CBS/Ideal properties to another party as the rights owner was a good friend... a heck of a lot of work, but now hopefully they'll have a chance at a new life. Yes, I'm that nameless "guy".) As for the possibility of pre-production samples existing for all of the other unproduced pieces, I'm confident that they are indeed out there, and there are likely multiple examples of each. A few years back I was at an auction where there was a nice quantity of bagged original Robo Force figures (only bagged, no boxes) which were sold in multiple lots, and it's quite possible there were odd pieces in there... regretfully (or not) at the time my thoughts were on older pieces, like one of my favorites, a really nice and minty Captain Video kid's outfit, and some 1960's toy packaging original artwork. I played with the toys of the 1960's (and earlier) and 1970's, so they tend to catch my attention.
