That inner bearing race design is similar to the one used on ball bearing front hubs on the smaller trucks. The seal surface is integral with the bearing race instead of the seal riding on the spindle or the rear axle load tube. Those older full floating axles were actually designed to have grease-packed bearings, and they usually had an outer seal that rode on the axle shaft or the snout of the load tube to prevent rear end oil from getting to the hubs. A recent thread in the big bolts forum had a discussion about finding those outer seals, which have a bolt circle that matches the axle flange. That cupped deflector isn't a slinger- - - - -it's there to drain any leakage through a weep hole in the backing plate to try to keep oil off the brake shoes.
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!