These 11 titles were the quickest way to get all known studio outtake material with minimal redundancies before Godfather released some new material. They are listed in order of their release:
TDOLZ's "Sessions," 2cd
Empress Valley's "Lost Sessions Vol.4," 2cd
Akashic's "Smithereens," 3cd
Empress Valley's "Lost Mixes EP Vol,7," 1cd
Empress Valley's "Lost Sessions Vol.8," 1cd
Scorpio's "Studio Sessions Ultimate," 12cd
Empress Valley's "Lost Sessions Vol.9," 1cd
Scorpio's "Atrocity Exhibition," 4cd
Empress Valley's "Making of LZII," 4cd
Empress Valley's "LZII Multi Track Mixdowns," 1cd
Boogie Mama's "Alts & Takes Volume One," 1cd
Adding the Godfather box makes twelve titles:
Godfather's Studio Magik," 18cd
To use the Godfather box in place of Scorpio's box, seven of the other titles mentioned above will still be needed, plus another title containing the Southampton material.
Notes on why each title is needed:
TDOLZ's Sessions presents 36 minutes of undocumented Battle of Evermore material.
Empress Valley's Lost Sessions Vol.4 debuts drum tracks from In Through the Out Door's rehearsals.
Akashic's Smithereens includes an outtake of The Song Remains the Same (cd3, track4). It also includes all of the new material released on EV3, making it fully redundant. (EV3 included a more complete version of the new track released on "All That Glitters is Gold," making it fully redundant.)
Empress Valley's Lost Mixes Vol,7 provides 2 mixes prepared by Jimmy while producing Coda.
Empress Valley's Lost Sessions Vol.8's only contribution is Poor Tom. It's ending is a few seconds longer, but is most likely explained as a mixing error. The other material on the title can be found on other titles, including Coda.
Scorpio's 12cd title debuts almost 18 minutes of new tape. It also fully displaces the following four titles:
Antrabata's "Studio Sessions," 11cd
Midas Touch's "Brutal Artistry," 3cd
Midas Touch's "Brutal Artistry II," 2cd
Empress Valley's "Lost Mixes EP Vol.1," 1cd
Empress Valley's Lost Sessions Vol.9 debuts a Stairway To Heaven outtake.
Scorpio's Atrocity Exhibition (fourth disc) introduces another 13 seconds of The Rover and 3:12 of the drumming and organ segment that follows Surrender.
Empress Valley's Making of Led Zeppelin II releases various instrumental and vocal separations for four songs
Empress Valley's Led Zeppelin II Multi Track Mixdowns mostly provides fully mixed versions of the four songs that are different from the album versions.
Boogie Mama's Alts & Takes Volume One offers full mixes of the four songs from LZII, with and without vocals. Each of the eight tracks are different from all other versions.
Godfather's box releases some new material (go to that page to see inclusions and exclusions).
(Many of the LZII "mixdowns" are highly similar, but are often slightly different from each other from one title to another. It's not widely known if these were all mixed while Led Zeppelin was together, or afterwards. They are all included here for now.)