Bullpup slide grip prototype

I recently converted a Mossberg 500A shotgun into a bullpup configuration using an aftermarket stock kit. The slide grip texture and ergonomics left a lot to be desired so I decided to design an adapter that would allow a Houge rubberized overmold forend grip to be mounted to the slide. I was going to design end-caps that would be secured to the core via bolts that would thread into inserts in the core. I have yet to design the end-caps and probably won't since this concept was ultimately aba