...well, in Benny's case, I suspect a complicating factor was the constantly shifting status of production. Not only did it flip between film and live-to-kinescope while on CBS (partly to accomodate production of his weekly radio show), for most of that run it was either seen fortnightly (alternating with "Private Secretary" in the mid-'50s -- both programs were sponsored by Lucky Strike) or, in its first years, monthly. Weekly scheduling of the Benny show didn't happen until 1960. And the live-to-kinescope productions would not only have inferior picture quality to the filmed episodes, many of both were filmed or kinnied at CBS' Television City and featured sequences in which Benny stood in front of a curtain with CBS "Eye" logos; obviously, those episodes would probably have caused problems for syndication sales to NBC or ABC affiliates. On top of all this, as on the radio series, the Lucky Strike commercials were woven into the entertainment material rather than presented in breaks; of course, that was most accurately an editing issue, but the chunks taken out because of that would rarely be 60 seconds even each time, leading to a lot of oddly-timed films for syndication. Thus, I suspect most of the episodes that one or more of these elements affected were simply not offered in syndication packages, and the copyrights may have been maintained on only those episodes that were syndicated, under the assumption that only the syndicated episodes had any commercial value...