Post by Mike Scott Rohan
My mistake, it's the 1961 that's still on Myto, apparently.
Copies of the Myto issue of 1960 are still available:
I bought my copy from Norbeck and Peters, who probably still sell it. And once they are up and running again, Berkshire is likely to offer it again.
As for the Orfeo, it's likely to sound at least somewhat better, as they usually have access to official sources. The difference can be quite significant (e.g. the 1952 Bayreuth Tristan).
I would avoid the 1961 performance. Myto screwed it up somehow, inserting part of a 1957 performance with Gustav Neidlinger as Sachs and Walter Geisler as Walther.