Bear Family has issued a 7-CD/1-DVD 300 page book box set:

http://www.bear-family.com/index.php?cl=details&lang=1&anid=2540aed3fa9ea2c9fe9ee6083a9af9eb

Smithsonian Folkways has combined the 2 LP's of Spanish Civil War
songs on 1 CD to be released In a couple of weeks:

http://www.folkways.si.edu/news-and-press/sneak-preview-songs-of-the-spanish-civil-war-out-10-14-14

Best wishes, Thomas.