79 GMC K25 hub help

[Nontwisty396]

Question about removing hub/rotor assembly on a 1979 GMC K25 with full time GM10 bolt front diff.
Someone (long before I got this truck) installed DualMatic locking hubs on the beast.
My problem is that I need to replace the ball joints, but can't seem to find any info on how to remove the hub/rotor assembly.
I got the locking hub off, and the snapring off the end of the axle, and the lock-ring from the inside lip of the housing.
That's as far as I can get. Someone in the past has obviously had trouble removing the slide gear(?) as it's got a couple of pieces missing from the outer ring.
Can anyone tell me if I'm missing a spring clip or something? Can't seem to find any diagrams that show the assembly that I have.
The closest I can find is a Selectro diagram, but while the hub handle matches the rest of the parts are different.
The hub handle leaves a gap that could allow dirt/sand/water into the assembly, so I wonder exactly what kind of a bastardized setup I bought?
Thanks to anyone who can help!