There are teeth on the side of the free wheel hub #25. The teeth are not shown in the diagram.
The free wheel clutch is on the end of the differential left case #27
The air actuator pushes the free wheel hub clutch into #27 mesh with the free wheel hub #25, which is part of the differential case, and that is when the power is transmitted to the front wheels.

So to permanently lock the hub, I will have to get #25 welded to #27..

I feel I have it wrong somewhere.. but I figure I will get a better understanding of what's going on in there when I open it up..

I'm not too keen on that welding fix - not that it won't work, but that it does mean you can't take the diff pinions out if you need to.

Ah ha! So that's where the zip ties came into play, between the Ring gear #10 and the movable clutch right next to it.. The zip ties Rally_T-115 used just keeps the clutch pushed in..

But in my case, if the teeth on the free wheel hub or the teeth on the axle lock clutch are damaged, the zip ties will not solve anything.. So my options are either to weld or replace parts..

I can source a used front differential pretty easy, so I will have my mech swap around the Differential Case Assemble if found to be damaged. I will try keeping the free wheel hub system operation if possible..

Yup - the zip ties just keep the clutch engaged.