I did a slightly major overhaul on this model of machine, he showed some of that work in the given pictures, and I will write some characteristics of this sewing machine:
Durkopp 239-125 is an industrial sewing machine with triple transport. It is mainly intended for sewing heavier materials: genuine leather, faux leather, eco leather, thicker fabric, furniture fabric, materials for bags, tendes, upholstery ...etc.