Greetings from RojoLand!
Dunno if folks would consider it a "treasure," but in a recently-acquired load of old tapes from the 1950s I found the 13 October 1957 CBS-TV special "The Edsel Show," taped live off-air (with a microphone, unfortunately). And also unfortunately, parts of it had been taped over years later. Good news is that "The Edsel Show" is up on YouTube currently, from the original videotape (oldest known videotape program in existence!), so this R2R tape can be "restored." (Everything else in that tape lot was church services and baby talk, typical stuff.)
Take care,
—
J. E. Knox "The Victor Freak"