Thank you all for your insightful answers. I'm sorry if I've kept you in suspense. Although I still hope to partially rebuild the wheel, I haven't yet done so. Instead I set out on a ride today with the hope of getting a few score miles in and once I got out of range of traffic noise (ever-present in Capitol Hill) I realized I could hear a cyclic noise varying with speed. Applying the brakes made no difference; it turned out to be the spokes in the rear wheel flexing with uneven tension. So I turned around and bought a cheap wheel at REI to get me through. But, well, it doesn't fit my frame.

In related news, does anyone want to buy a frankenbike? I have a nice purple one with Columbus tubing for sale. Also, anyone looking to sell a reasonably modern 54cm touring bike to a poor student?