Chuck,
Adding a note here with a possible resource document that may be of interest to you, in case you haven't seen it before.
This
1-1/2 Ton Army Truck manual is accessible for free on the web and can be downloaded/saved for your use as needed on your truck. There are several missing pages from the original scanning, but I did see that there was info still present discussing the transfer case and controls.
Something I came across sometime ago while trying to research other info on the G-506 series trucks and hope you can make use of it.
Loved the video of the 1st drive!
Dan
