HE COMPLETE 1936 “Parochial Hymnal” by the indomitable Fr. Carlo Rossini (291 pages) can be downloaded from the website dedicated to the St. Jean de Brébeuf Hymnal, a pew book still forthcoming. Inside that book, you’ll find a simple accompaniment for Credo III:
* * PDF • ORGAN ACCOMPANIMENT TO CREDO III
For myself, I prefer the version posted on the St. Antoine Daniel website. As usual, the Nova Organi Harmonia version is also worth downloading.