The inital batch of Wilkinson Sword Woodlores were all mirror finished blades.
However as time went on the finish was left to a fairly coarse grit finish, I'm not sure but I think they carried on mirror finishing the maple handled ones longer than they did the micarta handled ones, your example is a later one I think
The only way to get a mirror finish on the whole blade would be to work progressively through the grits of wet and dry, and then buff on a buffer with polishing compound .
The problem with that being that you'd probably lose the etched emblems on either side of the blade.
regards
beach bum