Hello Steve - What a fascinating machine! It's like a hybrid of a transverse shuttle and a vibrating shuttle. Also the balance wheel isn't attached to a separate crank so you only get one turn of the wheel for one turn of the handle instead of the three that you would get with the crank - you will really feel the difference when you start sewing with it. The bobbin winder might well turn out as being the most efficient you have ever used. It is very similar to the winder on my Serata treadle, which winds a far tighter and more even bobbin than any Singer.
German machines are so beautiful and intriguing. Congratulations on a wonderful find!