Hi RolandRat,
As far as CCKWs go, unfortunately I can't give you any help as mine is an open cab.
Installed a fair number of windshields with rubber gaskets in light and medium duty trucks - back in the days before they were installed using urethane adhesive.
The ones that I am familiar with have an expander strip, that fits into a groove on the outside of the rubber weather strip. Once the windshield and weatherstrip were in the body, we used a small tool that looked like a bottle opener, which would spread the groove in the weather strip, and push in the expander with one motion.
I'm thinking the CCKW probably uses the one piece weatherstrip? You might want to try the "rope trick". I have never used it personally, but it is described here:
https://www.stovebolt.com/techtips/win ... tall.html
Speaking of windshields, you may find this story amusing. When I first got my truck, there was a stone chip in the windshield. So, I just removed the hinges, popped it off, and took it over to the local glass shop so they could repair it.
When I arrived, the conversation went somewhat like this:
Me: Hi. I have a stone chip in my GMC's windshield that I would like to get fixed.
Them: Sure. I will need to look at it. Where is the truck?
Me: At home.
Them: Sir, you need to bring the truck in, if you want us to fix it.
Me. Well, the truck is at home... But I have the windshield here.
Them: (Somewhat confused) Your truck is at home, but the truck's windshield is here?
Me: Yes. I removed it from the truck, its in my car.
Them: (Very animated). Sir!! You didn't have to do that!! We could have just as easily fixed it while it was still in the truck!!
Me: No.. No... You don't understand. It is an old military truck, and the windshield comes off very easily.
So I took them out to the car and showed them. Then, we all had a good laugh as they had thought that I had actually cut the windshield out of a new truck, just to bring it in for stone chip repair. The techs all thought is was cool to work on the windshield of a 70+ year old army truck.
But the fun was not quite over. When I picked up the windshield later in the day, I went to the cashier to pay for the repair.
Cashier: Sir, you'll be glad to know there is a lifetime warranty on that repair. I just need some information for the warranty. Now let's see, that was a GMC truck, right?
Me: Yes.
Cashier: OK. What year is the truck?
Me: 1944.
Cashier: Huh ?
Me: 1944
Cashier: (puzzled) Uh.. O.K... What kind of GMC truck ?
Me: A CCKW.
Cashier: Uhhhh... Is that like a.. uhhh... Sierra ?
Me: Sure..
Cashier: And what is the VIN?
Me: Well.. I'll just give you the registration number. 4625319-S.
Cashier: And ?
Me: That's it.
Cashier. (Impatient now.) No. There has to be more numbers...
Finally the Tech walks up & chimes in and tells her its OK.. Just complete the sale...
I still crack up when I think about that...
Best Regards...