Hah!  Fixed it!  There were about 8 keys that weren't responding or wouldn't respond without firm pressure.  I just desoldered them, popped them out, opened them up, bent the 2 prongs outward, then reassembled.  It was super easy to do, only took about 30 seconds a key cap once I got it down.

The 8 keys I worked on have a much more satisfying key action, with a better tactile "pop" compared to the other keys.

Works great now.  Time for some Retr0Brite.