I received part no. 285565 Agitator Kit on order no. 302587 and have a question. The exploded view picture on page 2 of the instructions that came with the (Assy) shows a O-Ring part no. AP2906713 that I cannot find with the parts received. Is this a separate part from the seal that's under the bolt that secures the assy. to the shaft? The sales person I ordered the part from said the Assy. should be assembled and not separated parts in a box. When I opened the box, which was much bigger than necessary without any packing, the parts were loose and separated. Is there suppose to be this O-Ring included within all these parts? Should the Assy. been tied together to prevent separation? Should I order the O-Ring separately? I also found a black piece that I cannot find in any of the parts diagrams. Where does this part fit or was it not suppose to be included in this 'Assy.'? Thanks...