You'll need the time.
Via Nodwick, I have found the Doctor Who Scarf Site, a fan site with resources to support anyone who actually wants to knit one of Tom Baker's monster scarves. The author also has photos from his trip to Long Island, New York to view the original scarf that Baker wore in the first couple seasons of his seven-year tenure (Season 12, or L in some reference materials).
That's the pattern, there. In some of the photos he took in New York it's been patched in several places, so obviously its time as a piece of costumery was hard on it.
And the most amazing thing, I think, is that these have all been apparently kludged up from merely watching the shows in question and making notes. These are some serious cosplayers, here, folks, exercise caution.