Hello Ken
Many thanks for your answer. I turned it on its side, removed the bottom plate and turned the hand wheel. The gears seem OK until the nylon gear wheel underneath intersects with the gear wheel right under the needle plate. At that point it's obvious that some of the teeth have sheared off the second gear wheel - I mean the one that is vertically under the needle plate. I wonder if I could replace it? It looks as if it could be taken apart with an allen key. Hope this makes sense? I'd rather repair it than give up on it...
Miranda
July 2011