I have a RR-4 from 1971.
Wow, that's exactly what my grandparents had, I recognized it instantly from the picture.
My grandfather loved gadgets, he had everything. The first color TV in the family, the first microwave oven, all those silly widgets they sell at the county fair. Electric carving knife, crepe maker, waffle iron, sandwich maker, soda maker, hand mixer, electric knife sharpener, electric can opener, automatic apple peeler, you name it, he probably had one.