I've said this before, but I'm surprised they didn't do this decades ago -- remake some of the lost First and Second Doctor episodes as adventures with the current Doctor. There were some older series that would remake their own past installments, on the assumption that the originals would never be seen again and the audience that had seen them the first time had aged out and moved on. For instance, the '40s Superman radio series remade several of its stories multiple times (and a few of them were then remade as first-season episodes of the '50s TV series -- for instance, the "Superman on Earth" premiere episode is almost verbatim the same script as the origin story that was done several times on radio, and "The Stolen Costume" is an adaptation of a half-hour radio episode that was itself a trimmed-down version of a longer serial storyline from years earlier). There's a late-season Mannix episode with William Shatner that's a remake of a Mannix episode from the first or second season. And there were some older comics, from Gold Key and other publishers, that would just reprint older stories, sometimes with the dialogue and character names changed, and pass them off as new stories.
So just imagine if they'd, say, redone "The Myth Makers" or "The Power of the Daleks" with Four, Sarah, and Harry, or "The Celestial Toymaker" or "The Moonbase" with Five, Adric, and Nyssa. Just imagine how that would blow the minds of modern, continuity-obsessed fans trying to make sense of it all. (The closest equivalent we have is the Eighth Doctor audio/Flash-animation version of Shada, or the Tenth Doctor adaptation of the Seventh Doctor novel Human Nature.)
