When I replace a bearing with that extended seal surface with a tapered roller of the same dimensions, I just machine a steel seal ring that fits behind the bearing, and attach it to the spindle with red LocTite. It's a simple, permanent fix that eliminates the need for a scarce or nonexistent bearing.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!