This is what I thought but I get exactly what u mean
the difference between those two is not the gap at the bottom, it`s the hole in the middle.
the bearing material is what the washer on the shaft rubs against, the more material there, the less it`ll wear. take a look at the 270* bearing, there is about 90* missing from the material in the middle, whereas the one on the left doesnt have any missing from the middle (apart from the hole the shaft goes through).
compare those with the bearing you have. (not sure what degree you`d call that but it`s not full 360*).
