Designable Rail For Nerf Guns

So I was looking everywhere for just the base of an attachment for my nerf gun so I can design something on top of it but I couldn't find it anywhere so I figured I'd made it myself. What I would do is download this file then put it in something like Fusion 360 or Tinkercad or whatever you use to design stuff and build on top of it. The part is roughly 60mm long which should work fine for your needs but you can always adjust it for whatever you need. Side note I just want to see what happens if my post gets a comment so if you wouldn't mind leaving one just to tell me what you think or even just saying test that would be much appreciated