There's also a bracket below these two metal pieces that it taped down that goes around the two screw standoffs at the very bottom. My aftermarket case did not allow me to properly seat this additional bracket. I'm not entirely sure what it does.

Do you have issues with reception?

Isn't the cellular antenna on the bottom portion (connected via the smaller antenna type connection at the bottom of the main board)? I ask because after replacing my back housing I get a bar or two less than usual so either I missed something or the aftermarket housing I bought isn't good enough. The only thing that didn't fit properly with mine was a metal bracket that is actually below the two mentioned on Step 70 didn't fit properly around one of the standoffs which left me to believe something might not be contacting properly. WiFi and GPS seem to work perfect. This guide seems to end prematurely.