I have a theory as to why the monsters are dressed in 50s/60s clothes

Been rewatching the series to get ready for season 4 and I'm currently on episode 4 of season 3. While Victor is telling his stories to Sarah, he tells her that the Boy in White told him to take something of importance from the victims of the massacre when he was a kid.

What I'm thinking is that there is always some sort of massacre that is used as a "reset." Perhaps after each massacre, the monsters assume those bodies. In order to do that, I think they need to have the items of importance. Hence, why there are all of those random items down in the tunnels. But since Victor took the items himself, the monsters were forced to stay in the previous iterations bodies.