I've never seen one available as a new part from anybody. The only way the dealer sold them was as a hub and drum assembly but they've been discontinued for years.
moparmarkk,
If Cudaowner didn't take you up on the offer, I could use a spare 10" hub for my '65 Dart, and I'll pay. Both hubs failed on my '69 Dart long ago (9" drum, races spun), so smart to have a spare. I also want one to mock up an idea for a disk brake conversion that will be much less cost than brands x,y,& z.