Japanese pressings of "Live at San Quentin" are around. I have one and it sounds very good except for the scratches; bought another copy, American, that is pristing but it does not sound as good as the japanese pressing. Both are more than adequate for listening, however; it is the performance that counts. Cash's version of Dylan's "Wanted Man", "The Wreck of the Old 97", and "Starkville City Jail" are are first class as well as the great ballad with June Carter "Let There Be Peace In The Valley".
We all miss Johnny. I was fortunate enough to see him at the Fillmore in San Francisco when he was doing his first "American Recordings" tour.
