One entire display case was filled with items of Pope St. Pius V, including a mitre, stole and this breviary, which was St. Pius V's:
In addition, there was also this solemn Mass set of St. Pius V:
(Sorry for the blurriness, it was difficult to take behind glass)
The bottom two images better show the textiles used and also the heraldry on the vestments. The use of the particular heraldry of a Pope, Cardinal, Bishop or Canon is quite common within Rome and Italy generally I have found.