I added page scans for the 1906 Missionary Hymnal from the scanned version at Internet Archive. This is in part an test to see how it adding page scans from IA goes.

Summary: it works! It took some messing around for me to figure out how to get the images out of Internet Archive, how to convert them to a usable format, upload, etc. However, it can be done and it probably only takes an hour or two for a typical hymnal. There are hundreds more scanned hymnals at Internet Archive -- anyone interested in giving it a try?