When in doubt, ask the source ...
Last week I wrote to the Procuratoria of the Treasury of San Marco asking for more information about St. Peter's dagger. It may have helped that I wrote it on the stationery of my employer, Temple University, but I got a kind reply back this morning. This note accompanied two PDF files:
I send you some information about the so called St. Peter’s Dagger, which is kept in the Treasury of St. Mark’s Basilica in Venice.
These pdf are taken from A. Pasini, Il Tesoro di San Marco in Venezia, Venezia 1886, and from Il Tesoro di San Marco. Il Tesoro e il Museo, ed. by H.R. Hahnloser, Firenze 1971.
Kind regards,
Chiara Vian
Procuratoria di San Marco Biblioteca
The two PDF are attached below. Unfortunately for me they are in Italian. I hope one of our forumites will translate them.
I will post the full PDF files as JPGs later today so that you don't need to download the files.
Ian.