New house to me, the house was made in 1973, so the pool can't be older than that. I bought a new skimmer, but it just sits on top of these two holes, and doesn't seal. I looked at a few youtube videos and it seems there should be more housing that the skimmer valvue float thing sits on top of, almost like some sort of cover plate is missing. Is that replaceable, and if so what's it called, or does the whole housing need to be replaced?