The decoration of the porch of the collegiate church, which depicts the Annunciation of the angel Gabriel to Mary, has undergone several transformations over time. The original 18th-century decor was covered in 1816 by the magnificent mural paintings by Carlo Cocchi, which are once again visible today. In 1982, Cocchi's paintings, which had been overpainted with a Neo-Gothic decor in the 19th century, were brought back to light by the Crephart studio. During 2023, the supporting structure of the eaves was reinforced and urgent plaster consolidation work was undertaken following recurring issues with cracking and falling plaster. The mural paintings of the eaves, the soffit of the arch, and the porch wall were stabilized: the polychromy was dusted and cleaned, paint blisters were stabilized, plaster detached from the substrate was re-anchored, and gaps were filled. The parts restored in the 1980s that had faded were reconstructed, and the old, heavily altered retouches were corrected with light, delicate touches.