Singer Manufacturing Co. Sewing Machine - 99K, Serial #EL903366

This sewing machine was passed down to me by my mother. It was used by her and by me when I was a little girl. Can anyone tell me anything about the history and/or manufactured capabilities of this machine? It is in the original cabinet, except that my Mom "antiqued it" when she went through an "antiquing phase" (she also "antiqued" our upright piano! - haha). Though I have never used it in the years I have had it (about 15), I have no reason to believe that, with cleaning, it would not work. Thank you very much!