The only psalm and alleluia collection of his that I am aware of are simple psalms and alleluias in the Ignatius Pew Missal. He has some on his website, but they are an odd assortment of dates and saints days
There is the simple selection included in the Pew Missal. If you go to the Pew Missal website, there is a section called Music Downloads that you can get the more complex version of the psalms for the whole year. The responses are included in the back of the missal right after the hymns. I don't know about any other gospel acclamations of his though.
You can order Fr. Weber's Responsorial Psalms and Alleluias (as present in the Ignatius Pew Missal) from this website. The freely available "Alternative Psalm Book" has the more melismatic psalms but no Alleluias.
Furthermore, there are some (but not many) of Fr. Weber's psalms on the Noël Chabanel Psalm Project: www.ccwatershed.org/chabanel/. You would have to look at each Sunday to find them.
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