Looking at your pictures, your machine looks like it has a flat face plate and that it is a smaller version of the model 66. That means that it is probably a model 99 or a variation of the model 99.
The model 99 is a great little machine. I have been looking for one to buy so that I could make it into a handcrank.
Before you use your machine, make sure to check out or have someone else check out the wiring. Because of the age of the machine, you may need to change the wiring so that you don't get shocked.