There are great new chant resources on the web of church music association of america:
Passio Domini nostri Jesu Christi secundum
Size of each PDF file is cca 1.8 MB. Chants are scanned from:
Officium Majoris Hebdomadae et Octavae Paschae cum canto
juxta ordinem Breviarii, Missalis et Pontificalis Romani
editio compendiosa i juxta typicam RATISBONAE
sumptibus et typis Friderici Pustet
S. Sedis Apost. et S. Rituum Congregationis typographi 1923
Updated 2007-02-10