Most of it is Manson. The following are fake: Another Brick In The Wall, Forbidden Fruit and Like A Virgin. See http://www.mansonwiki.com/wiki/List_of_fake_Marilyn_Manson_songs
The rest are however the real deal. The songs on CD 1 are mostly soundtrack contributions and B-sides, while the ones on CD 2 are acoustic recordings released as B-sides or bonus tracks on local releases (UK mostly).