If what I read online is true and Hartnell broke the 4th wall to wish the audience a happy Christmas, then I really wish Dalek’s Master Plan would show up someday. It’s nigh impossible for hardly any lost episodes to ever be found though, yes?
Unfortunately, the episode where Hartnell wished us a happy Christmas was episode 7, “Feast of Steven”, the only 60s Who episode that wasn’t telecined, so the chances of its recovery are zero. Fortunately every other episode was, so there’s at least the possibility.