If you look at the breakdown illustration above, you can see that the bearing slides onto the axle, followed by the hub. Once installed, the hub locks the bearing onto the axle. Then, not shown, is that the brake backplate retains the bearing outer race, and holds the seal that rides on the lip of the hub. So, once the brake backplate is removed, the bearing is free to slide out. On Steve's differential it was stuck from years of gummy build-up, but there is nothing solid holding it in. There is no axle lock in the center pumpkin on the Lockheed...it simply slides into the splines. The ball bearing (not a tapered bearing) does all the work of holding the axle in place.
The Lockheed axle was weaker than the later Girling and it leaked, but it was much easier to service than the Girling. You could easily carry a spare axle and a handful of tools, and change the axle in less than an hour on a clean differential.