I have a Bluetooth Keyboard (MC184LL-A) which works perfectly. The end cap that screws into the left end of the keyboard's battery compartment became unscrewed and has been lost. I need to find someone that can help me obtain another "battery compartment end cap." I went to APPLE and they said the end cap doesn't have a part number so they can't help me. they suggested someone may know of a broken unit that I can get the end cap from.