I think the major sticking point would be finding a good fabric match (not to mention on his vest and cravat!) - but if Magnoli or someone else can do that I'd say that's half the battle conquered right there.
The pattern is very close to the type of frock coats Tom Baker wore between Season 13 and 17. But the whole costume is a strong callback to elements of the first four Doctor costumes, with a dash of the Sixth & Eighth. The Grey Tweed frock from late Season 13 and early Season 15 springs to mind the most with the dark collar accent.