Worked first time!! Amazing! I'd like to see on the "Add a new search engine" page a note against the "Search name" field that this is the 'Full name' of the search, and you go into the " about:preferences#search" page to add the @keyword in a separate step -- to remind me next time -- but it's easy enough to figure out; especially as, at least, Firefox makes it easy to remove mis-named engines! :-D