Hy Doug R. I believe the entire original inner bearing was a KA11424Z the cone you have, part number 17888 is half of the entire bearing the other half is cup part number 17830. It appears that the original bearing or its components have been unavailable since the mid seventies. Those inner bearings had a projection towards the spindle and that was the surface that the seal/felt rode on. I know that bearings of the same dimension are available without the projection, it was suggested in a discussion years ago to use these bearings and have a machine shop reproduce a spacer to position the bearing correctly and provide a surface for the seal to ride on, hope that helps.