I've thought about this myself. And we don't end up seeing the whole "diner" right? Please correct me if I'm wrong.

We only see partly of the establishment

Ye, just as I thought.

Well I think they don't appear in the diner but on the tv show and that's just tv show merchandise.

No one can proove that it is cc´s nightmares and not mike´s. If these are mikes nightmares, then he could mess them up with his memories from past. Mike´s foxy mask and others might be merch from the cartoon popular to that time "freddy on tour" or "fredbear n friends"

Hmmm I think the ''Freddy on tour'' show are from the fnaf one location because they look so similar.