Looks like You need a new case or perhaps pump body That pic is fuzzy and zoomed in too close.
Take the valve body, spacer plate etc for a better view and shoot a better pic of that area. Or just take it all apart and shoot a pic of that area with it empty.
ETA: looks like the band and rev drum are visible which is normal when looking through that window in the case. Not able to determine if you need a case or not from that pic. But if you do, is no big deal, they aren't expensive.
Post a pic of the piece of aluminum you found in the pan as well.
See my pics below for reference