[SS Tim]

Locking Hubs were of course optional.
The D44 axle used a hub cap (literally) to cover the end of the wheel hub enclosing the drive flange/drive gear and axle snap ring.
Here are some clips from the 68 and 72 service manuals to put a little perspective on it.
The caps should be nearly if not identical to the caps used on Full-Time/NP203 square bodies (pictured). The drive flange is something I'd need to dig for to find a picture. Just about any part-time conversion article for a NP203 1/2 ton ride should have pictures of the flanges.