I do recall a movie named Shazaam back then. I don't recall personally seeing it, but it did have an ad campaign on kid tv channels back then.

Also, if the movie doesn't exist anymore according to the narrative controllers, then I strongly suggest you digitally rip and convert that VHS into an mkv and distribute it freely. After all, you can't be accused of copyright infringement if the thing you are"illegally" redistributing doesn't actually exist.