3rd Row (and an unfortunate mishap resolved)

And the third row is in place! And at this point, i realized that i had soldered in all 16 switches sideways.... after a frustrating toil with a pair of wire cutters  i was able to cut the pair of contacts forming the short circuit on all of them.  Moral of the story- check the orientation twice before soldering!

Here you can see my high tech method for securing the buttons in their proper positions while the hot glue sets.