That wasn't the Master trying to stop the Harold Hardrada, so that Harold Godwinson would be well rested for Hastings, but another guy-with-a-Tardis - I don't think they had got around to Timelords and Gallifrey by then. The other GWAT was actually well-intentioned, unlike the Master Nb I'm not that old, only a few months older than the series, but they had a brief flurry of repeats a while back and that was one of them. They also did the Autons and the Silurians with Pertwee, but then they re-re-repeated "Genesis of the Daleks" and used the lower audience figure as an excuse to stop.