The selector button on the back of the camera allowing you to maneuver through the menu and review images broke off. I have a new selector switch but there is a cylindrical plastic piece with what appears to be a washer around the end that the central pin of the selector button fits into to keep it attached to the camera. I need that cylindrical piece but it doesn't appear in the nikon d300 repair manual. Does anyone have information on this piece? Specifically what it is called or how I can get hold of it? Excluding the difficulty in finding this item, it is a simple repair.