Mr. Mayer must not have reassembled one of these prior to his answer in 2010, regarding your problem with the antenna plate.
The plate has a tiny lip that must fit into the case precisely. It is very difficult to adjust into proper alignment. The most successful maneuver I have found is to slide the plate into a loose, ready position. Then, instead of sliding straight towards the top of the case (where the 2 dots are), slide the plate at a slight diagonal to the right with enough pressure for the entire lip to ease into place.
This may take a couple of tries to get right. When it is, you'll be rewarded with a slight "Thunk!" as both ears slip into place on either side.
Then screw in the two 5mm T8 Torx screws first, then the Two 6.6mm T8 Torx screws.