Good call with the Fowlers parts list - just what I needed!
Going by the part numbers, the early/late forks used different springs, spacers and dampers along with the caps, so now I know which parts need to stay together
I had wondered if the yokes were perhaps damaged in the crash. The stanchion kept binding in the lower yoke and took a lot of effort to slide when I put the test forks in... hopefully minimal as I spent yesterday welding up and grinding the steering stop back to shape after the crash forced the stops on the yoke through(!) them.
When rebuilding the forks earlier in the year I went with 15w oil, definitely improved things over the original without adjusting, shimming or otherwise meddling with the spring preload.