It was a long time in coming, but thanks to all the helpful instructions, re-wiring is complete and turn signals are a go. I was lucky to discover that my light assemblies were set up for 2-filament bulbs, so I saved some expense there. Those wiring harnesses are not as foolproof as claimed, there was more than a bit of patching and soldering to make things fit, but it wasn't terrible. Thanks everyone for the input.
