The new housing is correct and does not have/use a seal in it, the only housings that had the upper seal are the old aluminum housings and a few select plastic housing that are flat on the top where slinger fits.The later housings with the raised area( where red arrow is) do not need a seal as they use the small labyrinth seal on top/bottom of impeller to seal against wear plate and top of cup in housing. Use what you purchased as it will work and picture you posted looks like a plastic housing that has melted from a dry run as the cup is recessed. The "slinger does two things: (1) help keep trash and exhaust from getting on top of impeller and (2) the most important is to keep water from climbing driveshaft and getting into crankshaft splines. That why some driveshafts have a o-ring groove to stop it from entering splines or a crankshaft seal in a housing pressed into spline end of crank.
