... they are applied to the deck of the tub. See the angular shape to the right of your red circle, that is the gun shield. The gun platform does not extend forward (much) from that point. You are seeing the deck inside of the tub with ready racks above. It is most likely covered with non-skid pads -- think of the sandpaper like floor tiles you get at the hardware store and apply to the stair treads on your back porch.

Above and Below Graphics makes various sized decals of these pads in the popular ship scales. Their website says they are pausing shipping during the Canadian Postal Service job action. Check back later.