Just recently(4 days ago to be exact) a new review of the film appeared on IMDb. The author is claiming to have known Lee Groban for over 25 years. If somebody's interested they could try messaging the author of the review about the film. I would do that myself, as I've just recently heard about the film and read this thread, but I doubt my skills in writing official mails/messages in english.
https://www.imdb.com/title/tt0284020/reviews
https://www.imdb.com/user/ur21099471