The problem with newer (than 1950s) machines is that a lot of the hand wheels and drive belt part are encased and it takes alterations to make a hand wheel which allows room for the leather belt. If it's a model that easily adjust to this it's fine. Most treadles are made to turn the hand wheel anti-clockwise, but this might work just as well both ways. If it's a particuarly nice model it's well worth having it rewired and motor repaired.