I am in the process of building another pulse rifle. I purchased a WE gas blowback Thompson M1A1, and a APS CAM 870. I have a Matsucorps aluminumized shroud set. Ihave misplaced the screw tube and screws that connect the two shroud halves together. I've been to several hardware stores and can't seem to find the parts. Does anyone know where I can get the screw tubes and screws?