I have had a 503A since 1964 which I bought from the Singer Store in downtown Binghamton, NY. It was their machine used for sewing lessons and they were selling it to make room for the new models. I have loved this machine and will never part with it. It is rugged and sews like a charm. The only thing that went wrong is the release handle to disengage the needle so the bobbin could be wound froze up. My dear husband fixed it one day when he heard me complaining. I had to replace the bobbin winder rubber wheel. I would not hesitate to buy it.