Side window retention means firmly but flexibly grasp the edge portions of each side window and thereby utilize the windows as structural members to add {HEAD ~ strength} to {TAIL ~ the showcase} 
to
Side window retention means firmly but flexibly grasp the edge portions of each side window and thereby utilize the windows as structural members to add { HEAD ~ strength } to { TAIL ~ the showcase }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL