After an hour online with Apple Support, and several restarts, and throwing away anything in the two cache folders, resetting the parameter ram, etc. etc. It came down to three files in the Launch Agents and Launch Daemons folder. I had removed an old installation of Parallels from this laptop but left these files in place. After a few restarts and letting the Mac reestablish the cache files the shutdown is now about 2 seconds. I guess software manufacturer will have to start including uninstall utilities with their programs….
Check all “Parallels” junk software remains pieces in directories listed below and remove them.
MacintoshHD / Library / LaunchAgents
MacintoshHD / Library / LaunchDaemons
MacintoshHD / Library / Preferences