Take the flange out (again!) and take the flange and the seal to a good bearing shop. There's got to be a few in Toronto, because there's two in Chatham. Get an oversize seal with a wear ring, comes as a kit. You'll wind up with a thin sleeve that is almost a press fit over the worn spot on the flange (Should come with the tool to push it on). Pretty standard fix to a worn shaft. The only question is, is it available in the size you need? That's why you need to take the parts with you, so they can take some measurements.