Thanks for the suggestions, Max. I pulled the cluster out again yesterday and checked it. It turns out that the gauge overlay was barely touching the spindle for the speedometer needle. If you blew on it, it moved fine and it seemed to move freely when turning it by hand. I guess that slight friction from the overlay was enough to keep the speedometer from working. I *very* carefully trimmed the overlay away from the spindle with a razor blade and it works fine. I appreciate the help! :)