Some new information. The problem is Bridgeport.
I just tried my hand at another inventor, went to Bridgeport, completed the opportunities and lo and behold, no simbot option on workbench. I then tried my old inventor, who did knew how to make simbots, and moved him to Bridgeport and guess what? no simbot option.
I then moved the old inventor to twinbrook, and it was perfectly able to make em bots, after that, I moved the youngster to twinbrook (from a save before completing the opportunities), and after completing them he was perfectly able to play frankenstein.
This was all with the windows worldwide version of the game & ambitions, with NA late night.