Got it!!!
It turns out the previous owner had removed most of the relays (No, I've no idea why either)! But replacing them gave me a working rear window wiper and driver's side window, and I've been offered a complete set of switches which will get the passenger side one working too. I can cope with windie ones at the back for now, but will keep my eyes peeled in the scrapyards for Civics from which I can grab a couple of electric regulators and associated wiring.
The Powerflow exhaust is now on the car and I've been commuting in it for a couple of days. Oh what a nice place to be! Feels so much more serene than the ZR - it floats rather than crashes. I'm going to enjoy this...