Solved it. It was a fuse after all, just not the 'cluster' fuse. I had checked continuity with a multimeter without removing any of the fuses beside the one marked 'cluster', and all indicated that they were okay. I tried swapping out the 'room lamp' fuse after studying circuit diagrams, and everything is as it should be. That turned out to be a simple fix, to my great relief.

Sorry to bother you all, and I hope my experience will help some future troubleshooter. Pull 'em out before you test 'em.