Abstract: A structural body for a water-handling fixture assembly is alternatively usable as a right-hand or a left-hand body part in the assembly. A first edge of the body part is formed to orient in the assembly at an angle that is non-perpendicular in a first direction relative to a surface portion of another structural part of the assembly. A second edge, opposite the first, is formed to orient at an angle that is non-perpendicular in a second direction, opposite the first direction, relative to the surface portion. Formed as a side splash structure for a vanity top assembly of cultured stone, either of the edges of the body part can serve as a back or front edge so that, on either the left side or the right side, the large decoratively finished surface of the side splash structure can face inwardly in the vanity top assembly.