Brians price for working on a J3 is exceptionally good. If you have one that doesn't focus and you aren't comfortable working on it yourself, definitely get in contact with him.
I started out with a very nice J8 and eventually moved to a 1962 J3 when I found myself wanting more speed and more bokeh in some shots. The J8 from Fedka was great as is but the J3 purchased on ebay was slightly misfocused. He adjusted it and it is now an excellent lens. Fast, light, small, very nice sonnar image quality, etc. Both lenses can be excellent if you find the right one.