Singer sewing machine no. 66

Treadle singer sewing machine no. 66. The cabinet has 3 elaborately designes drawers on each side, and one flip down compartment in front. Has various original machine foot attachments, bobins, belt, owners manual (poor condition), and short cuts to home sewing book. Also had a plug in light attachment on the back made of plastic. From my understanding the person that the estate belonged to (95 years old) was the only owner of the machine. She stated that it worked until she replaced it with an electric, but would still use it from time to time. The machine was still threaded with a spool thru the machine from the last project she comoleted. I believe that it is the original finish and all of the pieces of the machine and carbonate are original. One small defect in the decal on the side and 2 small water rings on the top of the machine table when closed. The paint on the machine is bright and vibrant with minimal scratching or fading. My parents have the exact model, bit the cabinet was refinished by them because it was found in pieces in a barn...so I had to buy it because of the emotional attachment. I have been searching for a premium singer and cabinet for years, and I paid nearly nothing for it! Really love it! Hope you can shed some light on the value and what the light attachment is dates and if it is originally fabricated for this machine. Thank you for your time and efforts!!