[Dean 1993] proposes attribution to Johannes Brunet
V-CVbav-ms-Capp.Sist.45: Composer name in ms (index) = 'Brumel' [sic: incorrect attribution] / Composer name in ms = 'Jo. Brume[s]'; the 's' of Brume[s] above the [Superius] is erased / Title as in ms (index) = 'Ave maria gratia plena'