It looks to me as though the original wiring (left-hand diagram) was correct, as is the design of the outlet.

With the ground pin upward, the larger slot on the right is the neutral, which is the silver screw. The black screws linked together on the left can be used as a permanent feed to the recept and switch, with the top-right brass screw used as the switched output to some other device.

Alternatively, to have the switch control the recept, you can do what the original electrician did here and apply power to the brass screw, the black/tab left side then just linking switched power to the hot (smaller slot) of the recept.

Or you can break tha tab and wire the recept and switch into completely different circuits.
I'm not quite clear as to exactly what has been done to the grounding arrangements..... [Linked Image]