I inherited my mom's 15-90 (a 1939 model), the same machine I learned to sew on so many years ago. It is finally up and running after a couple of years of sitting idle. I could not lug it in to a service shop because the motor is connected to the foot pedal connected to the cabinet. But I found a wonderful guy, Ron, who makes house calls. He asked if I wanted to put in the treadle mechanism, but I declined. He cleaned and serviced her yesterday and she once again sews like the dream machine she is. I can't wait to start piecing on her! Ron said she should last another 60 years!