Look up industrial bearing shops, they'll have the seal. And by the way, are you doing a complete snout rebuild or just the seal?
If so, what new bearings are you using for the snout? I was told to get the NSK 6204c3x28 as the larger of the two bearings, but I live in Canada and Nsk doesn't carry them here and they have no plans of manufacturing them in the US. Are you using a different bearing???