Joan's actual dress from the movie
Debbie Reynolds has Joan's dress from Strait-Jacket in her possession. (there probably would have been 4 copies of this same dress...2 for Joan and 2 for Diane as she wore it also for the end scene). It was suppose to be on display at her new museum but no one is sure if it will ever open now since the company went bankrupt in Pigeon Forge.
here is the link:
http://www.hmpc.tv/thecollection_sciencefi.html