I have a Mossberg 500 breacher that I put an overfolding stock on. I found a working shell holder that mounts on the underside of the stock. However I want to find a side shell holder that fits with the stock when it is folded on top. I bought a TacStar 4 shot holder but the edge came up too high at the rear of the receiver and prevented the stock from folding over. Can anyone suggest one that will work with that stock? Also, I put a heat shield on it and misplaced the packaging. There was a little strip of plastic that they said to place under the heatshield at the front. Is that piece necessary? If so, any suggestions on what to replace it with?