Needing CAD or solidworks files of the magazine release button.
Why? It is a pretty simple part. All you need is a pair of calipers and you can get the height, width, thickness, and radius on the top and bottom. The threaded hole is of course centered and countersunk, you will have to find out the thread pattern. You can get rough dims on the grooves on the front. I don’t have one on me to measure, but I can tell you the hole it goes into is .515 X .318.
Dustin
I want to take a mil-spec 3d drawing and modify the finger pad for an extended button.
Your best bet is to reverse engineer one. Magazine buttons fit pretty loose. As long as yours fits into the recess in the receiver and is basically the right thickness, you will be good to go. Remember that you can adjust the amount it sticks out of the receiver a good amount by how far you screw it on. If I remember I’ll try and measure a couple this weekend.
Dustin