I am repairing a drop-damaged Stihl MS180 and need a top cover. Apparently, there are two versions of this saw? Different air filter housings and top cover - see photo. Standard 170 / 180 parts do not fit. The one I need is the second photo - Larger protrusion on top and angled on the starter side. May have found one on ebay. Also, what's the difference betwen the 180, 180c, and 180c-be? My starter cover only shows 180.