I was trying to adjust the rangefinder on my crown graphic, and it appears that the screw I need to loosen is busted off. (See attached picture -- it's the one that says "To Loosen" with the arrow.) Any thoughts on how I can add a slot back to this tiny threaded rod? I tried supergluing something to it, but that immediately broke off. I also tried using a pencil eraser but it's on there pretty tight. I was contemplating trying to slot it with a dremel tool of some sort, but it's small enough so I doubt I could get a thin enough disk. Is this a replaceable part? Anyone have an old junker of a rangefinder they might want to part with? I know some people basically pull them off and throw them away, but I wanted to use it for some handheld street type photography. Thanks...