Took a load of appliances to the scrapyard Tuesday. When I backed up to the pile, got out, and looked down, this was laying there. I couldn't condemn it to death, so it came home with me!
The very first model was 1936. It changed over the next 13 years in color, wattage, speeds, escuscheon and circumference of motor. In 1950 GE changed to a more traditional positioning of the motor with a gray knob in front. The earliest model had clear glass bowls and a silver speed control. The red knob came in the 40's.
Any GE turntable will fit. I switch mine out with a Sunbeam turntable and use a Sunbeam bowl with the three beaters. It works better than the original GE bowl because it fits closer to the beaters.