The using the drawing above as a guide. The following has to be done. A two pistol ports, two ports for removing the shell case. This is the large round port on the side. and one on the rear of the turret opposite the escape hatch.
Looks like I need to redo the pistol ports. They are a little oversize. Also I the top view you will need to remove the grenade launcher to the right side of the turret hatch. This is an easy way to back the D model. Again comments are welcome.