Good stuff, thanks for details. I don't think he uses a glockenspiel in his Wilco set-up, but he does have a bank of 'crotales', bell-like, tuned mini-cymbales. (On One Sunday Morning he just uses brushes throughout and the glock part is done on keyboard.)
I love the details shown here of his two set-ups:
http://glennkotche.com/technical.php#wilcokit
Note there's no kick drum in his solo kit, he has a pedal beating the underside of his floor tom only! Here he is making full use of the solo set-up, starting with mechanical cricket, his treated snare springs being pulled all over the place at 5.00, and from 12.00 some amazing stick work, some sort of mouth tube that's used to change the pitch on one drum, a bit of crotale and so forth. Great demonstration of his inventiveness and technical ability:
He's using the stick/mallet I referred to earlier here. Something like this:
http://www.gear4music.com/media/17265/600/preview.jpg
He does use mallets a lot, and you see quite a few drummers doing this. You get a more muffled sound on the drums this way than with sticks, and of course a softer wash with cymbals.
You're right about his consistency, and your 'non-percussion outlook' is a very good summation. Great fun discussing the mighty Glenn! Wilco did so well finding him. If you've seen the amazing
I Am Trying To Break Your Heart film, the first shots of him in that are literally on his first day in the band. They must have known right away that they'd got their man.