The "hand painting" is really decals.....beautiful decals. I think many of the early motor driven ones used a motor and a small belt over the same drive pulley on the sewing machine. Very simply retrofit for areas of the country that were electrified. You could by the machine new with a electric motor drive or buy a retrofit kit. The Singer design is still manufactured in some 3rd world countries with a treadle drive.

In Haiti two years ago I saw a tailor in a town square who had retrofitted a modern, mostly plastic, sewing machine with a drive pulley and treadle. Wish now I had ask him if I could have taken picture of him working.