Fr. Bux was there, as well as Spain, as part of a pilgrimage organized by the same priestly fraternity. As part of this pilgrimage, he celebrated Mass in the usus antiquior and further gave a lecture wherein, according to report provided by the FSISA, he encouraged them to be faithful to the thought and liturgical teaching of Pope Benedict XVI. Fr. Bux reportedly commented that a young clergy is needed today, one which is faithful to the Pope and who know, in depth, the Holy Father's thought and teaching. The FSISA also report that Fr. Bux "told us what we can and should do to help the Holy Father's call for a new liturgical movement: be able to appreciate the treasure of the usus antiquior ["traditional liturgy"] and reflect on the reform of the liturgical reform undertaken after the Second Vatican Council."
Here are some images of Mass celebrated by Fr. Bux in the church of St. Elizabeth, Coimbra.
Source: FSIS: Mons. Nicola Bux in Coimbra