Thanks for the images. Yes it does look like NAPCO borrowed components from the WW2 era Chevy 4x4. There are a couple of slight differences such as the front axle to spring attachment arrangement and the speedometer cable location, otherwise the basic components and major castings look identical. Interesting to note that your axle hubs are 5 bolts vs the military 6 bolt. I wonder what type of parts concoction NAPCO came up to make that arrangement? Makes me think that there may be some GM off the shelf spindle and hub compatibility.
The attached images are from my 1941 Chevy GI 4x4.
