Rear window screws???

[zippeay]

Ok, I've searched and searched but I can't come up with anything. I wish I had a picture to show, I can take one tonight. However, last night I starting to Prep the inside of my cab for paint and I've been welding up a ton of screw holes the P/O drilled everywhere.
My question is about an inch away from the rear window channel "I have a 64 small window btw" there are scews placed about every 2-3 inches all the way around the window channel???
I've tried to look this up but 99% of the interior pics I've found only show the dash and seats. It looks strange and I have no clue what the purpose of the screws are because the window channes is spot welded together. I'm not sure if this is something from the factory or if the P/O did it. I want to weld up the holes and smooth it out but I want to make sure there isn't a purpose for it. I can't get anything up inside to see if the screws are holding something together or I would just weld them all up.
I would appreciate any help. Thanks!