Thanks to Josh Hawkins for this great picture of a MOTU movie exhibit featured at COSI back in 1989-
The case holds the masks for Gwildor, Skeletor, Beast Man, Karg, and the interior portion of Saurod. Apparently, the exhibit featured props and special effects material from various films under a "movie magic" theme. Here's what Josh remembers:
All I remember about the display was it was something about movie magic. There was also the Alien fighting Ripley from Alien and there was the Shark from Jaws. I remember being super excited about the MotU masks and begged my mom to let me see them. Gwildor was my favorite and Karg scarred the bejesus out of me (still kinda does). The picture is one of my favorite memories from my childhood because I feel like I was able to get closer to MotU than most other kids I knew.
What a cool find! And I have to admit, a bit of a bummer for me since I lived only and hour and a half away from COSI and had no idea it was there... If anyone else remembers the exhibit or has more pics of it, please send me an e-mail at firstname.lastname@example.org and I'll update this post with the additional info! Thanks again to Josh for sharing this!