I knew someone had to have made a custom of a vintage Castle Grayskullman (aside from the creator of CGM himself), and a cursory search brought up this one by Hunter Knight Customs. I think CGM is the 30th Anniversary figure that most seems like it would have existed in the 1980s – yes, even more than Draego-Man, who, awesome as he is, seems a bit more like something Remco would have produced in one of their high-quality knockoff lines, since they focused a lot more on the dragons and dinosaurs.