To me, it looks like the outer housing to a roller bearing, usually referred to as a race bearing. Though I don't know why as the part itself is just the Race while the bearing assembly is another part all together.
Anyway, the biggest problem would be finding the correct one. Some are beveled on both sides (like the one in the pic), but most are only beveled on the inner face (to mate with the roller bearing), while the outer face is vertical (to mate with the hub).
It could just be a piece that came off the derwent while they were scrapping that for parts as well.
-Fred