This is an Australian chant style mass that Chris is using successfully at his church.
Brother Michael Herry fms is an icon of Australian Catholic music and it is always worth a dive into his ridiculously deep archive, most of which is now freely available.
This mass being chant, it is pointless making BIAB backings, but thankfully it is not necessary.
He has full sung through tutorials and melody lines to guide you at Marist Music, so the choir and assembly can practice at home. The keyboard accompaniment can be purchased for download at Willow. There are no chords on the music so you have to be able to play piano or organ, no fudging, so lets me out I’m afraid. Of course, this will work best if your priest wants to sings their bits and get a chant dialogue going.