Alfonso de Vicente, in his music catalogue of the Monastery of Santa Ana de Ávila (1989), p. 68, among the works included in the book of polyphony E-Asa 12 [for piece E-Asa 12 No.8] annotated the following: "307. Fol. 34 v: MORALES Y DE LA REDONDA (?), Misa". In this database, the piece has been provisionally associated with Cristóbal de Morales and with an unknown composer named De la Redonada or from (de) La Redonda. According to DIAMM, the composer was not Cristóbal de Morales, but perhaps Rodrigo Morales; see https://www.diamm.ac.uk/sources/2795/#/inventory. However, since Cristóbal de Morales was chapelmaster at Ávila cathedral in 1526, it cannot be discarded that a hitherto unknown early composition by him would have survived in that city.
La Redonda, a village in the province of Salamanca, is 206 km far from Ávila, and perhaps the ascription of this missa refers to an unknown Morales (a very common name in Spain) from that location or the piece is in some way related to that village. The incorporation to the database of "De la Redonda" as a composer perhaps will contribute to clarify this ascription in the future.