I agree a CNC'd aluminum bracket would prob be best or a commercial 3D printer - if NASA can 3D print rocket parts, we can prob do it for a pump handle.
Keep in mind any rail should be long enough to mount a light (light/laser combo)
and a vertical grip. HiTech product has 14 slots to mount both - about 6 inches which is the length of the entire pump grip area.
dfariswheel - that diagram looks only good for a vert grip; 3" rail only provides 5 slots.
I could see an aluminum bracket that utilizes the bottom 2 of the existing 4 screw holes to wrap bracket around bottom of pump. this keep is lower and not wider.
I would like to keep things on center and avoid hard to reach side slots. So a longer rail for light and vert handle is my goal.
Thoughts?