UPDATE: Seller indicates it includes a Gov plate, so it was likely a Gov/military purchased CJ-3B.
This has a ventilating windshield. It does appear to have a place on the dash with four holes where a gov data plate could have been.
https://carbondale.craigslist.org/cto/d/marissa-m606-cj3b-military-jeep-updated/7087006238.html

“This is a 1964 Military Jeep for sale that is like a M606.
The army and the navy were the only ones to use these jeeps, and they were intended for more mundane duties around bases and such.
It does have the original military wheels and most of the original hard top (the side and rear doors are missing).
The engine is stuck, and the radiator is long gone (scrappers stole it along with the doors years ago).
I have the original body tags along with the reproduction brass military tag.
No title, but will provide a bill of sale.
Accepting any reasonable offer. I would like to see it go to someone who knows what it is versus it becoming a start for a crawler or mud buggy.”