FIG. 1 is a perspective view in a nested position. FIG. 2 is a top view in a nested position. FIG. 3 is a cross-sectional view in a nested position along the centerline 3—3 of FIG. 1. FIG. 4 is a side elevation view in a nested position from one side, the view from the opposite side being identical. FIG. 5 is a bottom view in a nested position. FIG. 6 is a front end view in a nested position. FIG. 7 is a rear end view in a nested position; and, FIG. 8 is a perspective view in an open position.