What year was Kenmore sewing machine model 1720 manufactured and what did it cost?

I bought this model not long after I graduated from High School and before I went to work at Sears. I graduated in 1971 and worked at Sears in 1973 and 1974, so I think it was probably in 1972. I still have mine and it still sews perfectly. You can find some of the parts online. I did have to replace the friction wheel on the bobbin winder and the foot controller.