There is an aftermarket bracket in, black, sheet metal that fastened where your back plate is missing. I have one just like yours. That plate held the light. There was a screw-on motor support (boss) that fastens on the right side. Mine was broken and I was lucky enough to find one at a sewing machine shop. DH is rewiring it for me. They are out there. As many 66s that have been junked, someone will have one. Watch Ebay (sewing machine parts) and junk stores. Good luck