The Corbin Russwin ED6200 Top Casting 494F91 was used on all of the ED6000 Series devices. In November of 2015, this device was discontinued, but this part is still available. The Top Casing is just made out of a die cast metal, and one flying kung-fu kick will break it.
Corbin Russwin part #494F91
ED6200-3700 PARTS BREAK DOWN