I don't expect a reply before I've done it, but maybe this will help someone
else, as I didn't see any Linux instructions, except for 
  apt-get update
  apt-get install webhttrack

I have uninstalled and then reinstalled. Now I find I need to open up port
8081. I'm sure it was on port 8080 the first time! I set Apache to listen on
8080. Now I will have to add 8081!