The 77 of the Dumfries and Appleby is wider than average; not sure if they class it class FX but the deeper toe box height and vamp with less outflare than the more tapered lasts gives it considerable volume. Still, they are country boots/shoes. I found the 89, of the Culford for instance, was reasonably roomy too although still not a wide fit.
To be honest, although us Brits typically I would say have a wider foot than Americans, I don't really find that many English shoes offer that roomy a toe box fit - wider widths just seem to offer greater width at the ball yet still taper in to the tip or nose of the last. The Sanders 4831 is maybe an exception, that is pretty comfortable to be fair.
I've given up on English RTW shoes. Besides, my personal feeling is that the price is heading too far north for something essentially factory made with a goodyear welt.