Not sure if anyone else has picked up on this yet but those who have seen the Bob Hope film Ghost Breakers may remember the part where they find the portrait that looks just like Paulette Goddard's character and they determine it is her ancestor. A very similar sequence occurs in the Ghostbusters game when they find the portrait of Shandor's mother and determine Ilyssa is a Shandor. it seems to me that it's very likely this part of the game was inspired by the film.