Haha! your thought on the 870 is the exact reason I liked the Mossberg idea, I have one!! Plus that makes it easier to pull the measurements from the gun itself for the rear of the main body.

Also, I just ordered this from Midway. http://www.midwayusa.com/product/217...ProductDescrip

I also was able to source out the billet here locally yesterday. Picked up a few pieces to play around with and drew the basic design. Now I just need to find a cheap butt stock for playing around with. All I have is the wood stock here.