UPDATE: As Barney notes in the comments, it appears to be a windshield adapted from a Mighty Mite. You can see an example here: http://www.ewillys.com/wp-content/uploads/2020/11/year-m422a1-imperial-ca1.jpg

Buz just acquired this MB that has an unusual windshield setup. I have seen some bubba jobs similar to this windshield, but someone did this much better than most. It does not appear to be an M-38A1 windshield (too narrow), but it doesn’t appear to be a CJ-3A/DJ-3A windshield (curved top holder). Anyone recognize it?

He described the windshield this way:

I bought this 1943 Willys MB with this unusual style M38A1 windshield assembly. It is narrower than the M38A1 windshield and this one has not been cut and welded. Also a very precise adaptation to the cowl to mount the windshield. No doubt it probably harms the value of the 1943 model, but it has to have been some sort of factory modification, it’s not a home brew bubba job. Have you ever seen anything similar to this?  I have the history of this jeep back to 1947. The first civilian registration was issued in 1947 to E. W. Worrell who paid $800 for it in Hillsville, VA.

Here are some pics.