More fun with electrics. While working to refit the dash today, I installed the gauge cluster for testing. And everything worked... at first.
While testing all the warning lights, suddenly I caught a whiff of magic smoke escaping, and the dash illumination lights all came on by themselves, and would not go out. After pulling the cluster back out I found that there were some rather crude repairs to the printed circuit at some of the bulb "sockets", and one of them shorted and burned a section of the circuit. [Big sigh!]
So add another foreign country to the parts sources list. So far I've bought parts from Germany, England, Denmark and France. Now I found that there is a shop in Australia that has reproduced the printed circuit sheet for these cars. I've started the order process now.
While I wait, I removed the damaged traces so that I could install the gauges and drive the car while I wait. Apparently the only damage was to the dash illumination. I don't plan to drive at night, so I can get by until the new part arrives.