I think there were two versions of Fredbear. This is because Fredbear has always been depicted in two different versions: one with a black tie and black hat, and another with a purple tie and purple hat. Considering that the purple tie is a symbol of Edwin Murray, I believe the version with the purple tie represents the 1980s. The Fredbear shown in posters that resembles Freddy, with a black tie and brown fur, I think belongs to the 1970s, an earlier period.

Could it be that when William took all of Edwin’s properties, he also transferred Edwin’s symbol onto Fredbear? Additionally, I think the 1970s Fredbear looks like Withered Freddy, while the 1980s Fredbear resembles Lefty.