The RAI performance was recorded at a public concert on 30 April 1959. The soloists were Gloria Davy (soprano) and Pierre Mollet (bass), with the Turin RAI Chorus and Orchestra conducted by Mario Rossi. I wasn't aware of an LP issue. It used to be on youtube but seems to have disappeared. There are a couple of quite recent live performances on youtube, though. It lasts just under 36 minutes in Rossi's hands, so cantata is probably a better word than oratorio, also because it has only 2 soloists.