I also believe it's a clone of the singer 45k, but the necchi 643-110 doesn't exist. the important thing is to use a manual, so I will use the singer 45k. Can you tell me what maximum thickness I can sew? I would need this to sew the saddle skirts, 2 layers of 14 oz plus the shearling. What needles and maximum thread thickness can I use? Thank you