Looks like your axle is a second series 1956-59. The 56-59 does not have a bearing between the lower axle boss and spindle. They have a thrust washer. There are two parts to some of the king pin thrust washers looks like one part is missing. I think if you replace the king pins you will be ok. The king pin set comes with new thrust washers. Just make sure the new king pins are tight in the axle and have no movement.
