Just to clarify, these are the Dawn locking pins I'm on about. You can see the drive gear is fully home when the locking pin is engaged, as opposed the 9th Div jeep where it is partially out:
These pins are spring loaded and will engage automatically when you push the drive gear in, but only if they're well lubricated. If they're dry of lubricant like my high ratio locking pin they will jam and hold the drive gear partially out, just like a sticky door lock plunger jams on the striker plate. However it's actually much better that way because you don't have to disengage them when changing ratios, which would be even more of a nuisance on the jeep because you'd have to reach over to do it. The only reason I lubricated my low ratio locking pin is because the handle kept falling out when I did laps around the back yard. That can't happen on the jeep, so once the locking pins got a bit sticky through mud and dirt and water etc. you'd leave them that way deliberately.
Thinking further on the shaft attachment I don't believe you could weld it solid with such a long shaft, you'd need some movement in the joint to allow for the inevitable misalignment due to the moveable post, and also as the chassis flexes. That being the case they've probably gone about it in the simplest way possible, using the existing Dawn parts rather than designing and fabricating new parts.
Anyway nice work Tony, you've convinced me it was designed for high and low ratio use. As such I'm even more impressed with this jeep mod, maybe I'll stick the Dawn No.5 on the front of my F15A!