I think post-WW2 Corps of Engineers insignia with that "9M" on them. Probably the "U.S." devices, as well.  

It appears to be a US-made Vietnam Era example.

I hope no serious injuries to either people or DUKW 🫣   It could be worse; try explaining this to your insurance claims adjuster... 'Could you tell me what happened?' 'Well yes, I was merrily driving along and suddenly this Mosquito crashed into my windshield!'   Imagine the look you would get 🤣      

Very nice!!

The Vietnamese ERDL shirt looks to be the same one he wears in the picture (see the black and khaki color on the wearer's left pocket flap)! That is just phenomenal!   Thank you for your service, Jules

With that moveable ring drape ring, I would say it is an earlier (i.e. VN era) example.  Later ones are fixed - ring and planchet are all one piece. 

The 9M hallmark is 1950’s manufacture.    So, definitely not WW2.  

Still working on finding the contents of the leather spare parts box.

@Randy do you have a picture a certified authentic one ? 

Yes, the DUKW is a large and slow vehicle on the road, but in this case there's no-one to blame but the van driver who was driving under the influence of alcohol and cut the corner while there was enough space for two vehicles to pass on that street. Furthermore the bow of the DUKW had magnetic white LED lights for added visibility as shown on the photo below. It's just bad luck and one second earlier or later would have made a difference...