I'm not sure who else would really know this, so here it goes. I was wondering if there is another Catholic version of the Monastic Diurnal between 1949 (what I see around in certain places) and 1963 (the same version you'd see sold by SSPX affiliated Benedictines). Another way to put it is what was the final Benedictine Calendar version when Pope Pius XII died?

Sorry if these kinds of questions are out of place, but I seriously don't know who to ask.

Never mind. I stumbled across my answer on eBay recently. There was a 1955 edition that I bought, and a 1960 edition being sold by the same user.