I don't think are the following are on Testament CD; they're available as downloads now from Presto and other sources:
Beethoven: String Quartet No. 10, Op. 74 "Harp" (1956)
Beethoven: String Quartet No. 13, Op. 130 (1954)
I don't think Testament released all the Mozart and Schumann from the Italiano's EMI period, either. I know they went on to record all this material for Philips; I was just wondering if the sudden release of these 1950s recordings stemmed from some larger project.