If you are going for authentic, then you don't need hinges at all. (Unless you prefer them) Commonly, machines were just open in the back, and a sheet of wood that was the entire interior width of the cabinet would simply drop into place on the back and locked on the top simply using a cam lock. Other machines had hinges mounted on the inside of the cabinet, but were generally the entire interior width of the cabinet as well. The hinge would just be mounted on the interior side of the cabinet, with a cam lock holding it shut on the other side.