The inner spiders show signs of a leak. The picture makes it seem wetter than it really is. The inner and outer CV boots look and feel firm, with no tears, soft spots, or signs of leaking grease.
Some questions:
What's the more likely source of the leak, a diff seal, or an oil seal in the axle?
Any known reason for a mix/match of a bolt-on and can-style axle, other than perhaps that's what the PO sourced in a previous repair?
If it's the oil seal in the can, is rebuilding it worth it, or just go with a replacement axle?
No endorsement for the following link intended, it's just the only other place I've seen a "bolt-on" style spider. Everywhere else shows cans.
https://**************.com/node/6121
Car: '83 300CD, auto trans