Moved the last few machines off the 128 subnet, and did the inevitable tidying up, including troubleshooting chou's inexplicable behaviour (not bringing up apache httpd on reboot - thanks, Michael J).
DNS was a bit sluggish as well, so we didn't really know whether things had turned out for about 2 hours.
All is well now. Chou and rutabaga have returned, and I've removed the node for king-henry completely. If ETCL brings it back online I'll re-instate the node.