I've got a 1950s refurbished Singer purchased about two years ago a 15-125. How I love the sound of this machine. It's one of the green ones from the era when Singer felt it needed to compete with Japanese sewing machines coming out in pretty colors. It sews heavy duty very well. Maybe even better than my Kenmore 1660 which we purchased new back in 1977.
Five years ago this coming June I purchased a Singer 9960 for cheap. It was an Amazon special and I had some points, too. I never expected it to last this long but it's steady & sturdy. And it cuts the thread for you. I never thought I cared about that feature until the first time I used it. It feels like Singer can make a comeback if it wants to. Anyhow, when this machine conks out I'll just go back to my old Kenny and the new-old Singer 15-125.
Years ago I inherited my dad's 96-10 industrial. He was a master pocket maker back in the days when you could find a job in an afternoon sewing in Brooklyn or Manhattan. When he retired he bought this old machine from the shop since he was so used to an industrial's speed and strength. This Spring I'm having it worked on. A local friend found a great guy who worked on this model when he first started repairing sewing machines decades ago. I'm excited to get it going again.