Missing Johnny Carson Tonight Show Tapes

According to NBC officials and many other sources,almost all of Johnny Carson's Tonight Show episodes for NBC between 1962 and 1972 were erased after broadcasting.No archives were kept.By contrast,all of Johnny Carson's Tonight Show episodes between 1973 and 1992 have been archived meticulously and are available for reviewing.
                                 I hope that somehow many or most of the The Tonight Show Johnny Carson episodes between 1962 and 1972 will emerge out of nowhere or mysteriously reappear.What a great loss for television history if those episodes are irretrievably lost!
                                 Of particular interest to me would be the Johnny Carson Tonight show for  November 22,1963,the day John F.Kennedy was assassinated and for the whole week following that.