How to obtain Grothendieck’s “Long March Through Galois Theory”
After digging through tones of Internet material, I have answered my own question: currently, as of August 3, 2015, there is no resource on the Internet that contains all of the work "La longue marche à travers la théorie de Galois". Not scanned, not in TeX, not in PDF. There is only that which has been made available by Leila Schneps.
"Long March Through Galois Theory" can either be obtained from Jean Malgoire directly, or from a university library, or from the Université de Montpellier (there are reportedly some 20,000 pages of material from Grothendieck stored somewhere in a box).
An interesting resource I found is the archived web page of Malgoire: https://web.archive.org/web/20070211071321/http://www.math.univ-montp2.fr/agata/malgoire.html . It's in French, but you can use Google translate. Basically it states that he has all of the work, and that he is working on retyping it in TeX and publishing it.
Edit: As of 2020, all pages of the manuscript are scanned at Montpellier's University and available online at Archives Grothendieck.
La Longue Marche, Table des Matieres.
Github project to (TeX)-type a scanned copy of "La longue Marche, Ia #1-25.
La Longue Marche, Ib #26-37.
The first part is already complete. #1-37
Edit: There has been some changes in the same Mathoverflow question! Namely, a project for typing it.