I have one... from 1923. It is an old treadle, and still sews beautifully after 84 years. My grandmother got it the year before my dear mother was born. I have the old wooden cabinet that has the 'tippy' drawer in the front, and four long narrow 4.5" deep drawers. I rarely use it. I'm afraid I will break the leather belt that drives the treadle.
I have cleaned mine with mild soap (Dawn dishwashing liquid) and warm water. That's it.
Enjoy! They are close to works of art!
Anita