Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:2869232.

TWO!! Yes, you have two options for a Demolisher Picatinny Top Rail. I've made a simple skinny rail and a wide base rail that fills out, what I felt like was and odd tall gap. The wide model flows well into the body of the Demolisher. For both you will need to cut out the first stop on the nerf rail. This way you get a solid connection. I just used flush side cutters.