There are now 7 Masses on IMSLP by Martin G. Dumler (an early American Society of St. Cecilia favorite). They aren't PD in the US, but are in Canada. I've tapped out my library sources and am looking for more. I am particularly interested in the Missa Cantata Pueri, Op. 33, and the Op. 24 solo songs, but anything not up there is of interest. If you have something in your personal files that you could scan, this scholar would thank you. (Cincinnati Public is the unique library source for much of this music, but they won't let it out on interlibrary loan, and it's over 5 hrs from home to drive.)