So, good ending today. The shop called, I swung by, he got into the fuses...we are back working again. There are a few minor electrical gremlins, still, but at least I have turn signals again. He recommended I go through the engine compartment and clean most or all of the connections, advising me how to go about that. Now I can run the Spider about all weekend.
I have been systematically working my way through my wiring changing all the terminals for soldered ones, adding insulating covers. One I hadnt done anything to was the ones to the horn relay and because it was a lose fit one came off, so no horn. Where did this happen? The one place in the world where you really need a horn, in the Turin rush hour during my summer tour!
Daily drive is a Giulia 2.0 MA, wife drives a 939 Spider in the summer and a Abarth 595 in the winter. For special sunny days we have a S2 Spider Junior in the garage.