Thanks for the comments everyone. Alright here is the how-to.
First, I'd like to say plastic welding is hard, so it's not pretty, but it's functional.
Here is the top of the AFG each of the circles are about 2-3mm thick and are polymer from a mag. They are plastic welded and jb welded on. I'm not good at plastic welding that is why they don't look so good... at least they are strong.
Also, there is the modified backing to the screw for a magpul rail attachment, cut into the keyhole shape. The FDE areas are where I had to remove material.
The side cutout shows how the pieces were plastic welded on the seam in the middle, and where the screw lies in the "triangle" of the AFG.
Finally, I melted the polymer into the holes where the original screw went to make it look like they were not there.
Basically, the screw clamps the AFG don on to the handguard while the circle extrusions hold the AFG from sliding and twisting. When the screw is loosened the AFG can pull up and slide out of the handguard.
So, I tried to find an easier and better way of doing it for my handstop because i did not like the AFG on this particular handguard.
I was messing around and found out that the heads of the screws that would hold the AFG or RVG to the rail fit perfectly into the holes on the NSR.
The top cutout shows the slotted magpul screw acting as the circular piece that the polymer circle acted as for the AFG. Again, there is a modified Magpul rail attachment and screw below it. My camera made it seem as if the holes are crooked but they are really not.
Bottom shot. I still need to shave the screw down flush so it isn't so long.
Like on the AFG I melted and plastic welded material into the screw holes to fill them. I also had to plastic weld the piece that slides in and out on the RVG into the grip to make it one solid piece
A fresh coat of RIt Dye to cover the FDE and a little more finishing work and I think both pieces will be set.
My poor polymer donor.
More pictures of the gun. ( I'm no Stickman by any means )
~Ben