Choral Public Domain Library

I am interested in the SATB arrangements too, particularly Messner. Can you tell me if it's published or how I can get a copy? I found a sort of 'bootleg" one in my choir's library, but it looks like it's been chopped up a bit by a past director. The choir performed it several years ago; I'm tr...

I would like to use CPDL #5891, Rheinberger's Cantus Missae. The edition notes say it "needs updating with new Feb 3rd, 2008 files." How do I get that new (presumably more accurate) file? I'm a bit of a computer Neanderthal. - jlester