Wohoo! There be life in them old wires!!!
Thanks to Ed's unquestionable expertise, my KSU 551 is now fully operational. Somehow I had managed to blow the 10VAC fuse. Luckily there was a spare next to it. I also placed a jumper between CA1 and CA2, and I get two sweet rings.
All's good. Lamps flashing, bells ringing. I'm so happy I could cry! I really thought I had killed the unit by removing the jumper between MB and LB.
Arthur, obviously modesty is one of your virtues.
