From what i have seen and installed, manufacturers dont make interchangable parts when it comes to mounts and brackets. The mounting hole pattern on the back of the tv is about all the cooperation they came up with. There are even variations in a single manufacturers lineup.....
You will likely have to remove it and install a new mount backplate when you get your new mount. Best scenario is to find out what it was and buy the same one so you dont have to make new holes or drill new anchors. Good luck!
