Quite by accident I stumbled on the page https://hymnary.org/tune/plentge_schalk
The only use given in this entry is Catholic Book of Worship III #433. I checked my copy of that hymnal and the name is correctly spelled FLENTGE there. I think this needs to be combined with
https://hymnary.org/tune/flentge_schalk
Comments
FLENTGE/PLENTGE
Thanks, it is fixed.