[Arran]

Dan;
  I think that you placed the wrong knobs on your Westinghouse, the before picture shows the correct ones, the later ones show it with RCA/Canadian G.E knobs from the 1940s. I also have a Canadian Westinghouse model 512 in the project pile, it's a 512A
to be exact, models 512 X and 512X were console models, and the knobs are more domed like the knobs in the before photo. The 512A is a 1936 model, the 527A is a 1937 model which is similar but only has two bands and a more rectangular dial. In any event I think that the cabinet on my model 512A is a little different, I'm not sure whether it has the contrasting bands of veneer near the ends like yours has. The knobs on your model 683A are correct, Westinghouse made a series of sets using those concentric knobs much like the ones early RCA TV sets used between 1940 and 1949. Canadian Westinghouse's radio factory was based in Hamilton, Ontario, and as such was within driving distance to a number of furniture companies in Kitchener, Stratford, and Woodstock, so that probably explains the fancy cabinets they used.
Regards
Arran