I have a 3 gage (wind, speed, and depth) NavPod housing. I need access to the back of the gages for calibration of the wind instrument and to check the wiring on the spedo. I thought this would be pretty simple until I discovered that the screws holding the unit together are from outer space. They look like allen headed set screws but they have a little metal pin in the center that would not let an allen wrench work.Anyone know where to find a tool for these?