1. Singer 201-2 was purchased at an estate sale in 2002. The serial number dates it as being allocated June 13, 1950 (centennial badge). I haven't used it much because it's had problems with the built-in foot pedal that I haven't gotten around to fixing.
2. Singer 15-91 was purchased at an auction around 8 years ago. If I could only keep 1 machine, that would be it. Very close in age to my 201 as the serial number was allocated July 11, 1950 (regular badge). I never realized just how close they were in age! Both from the Elizabethport factory.
3. Singer FW was given to me by my mother about 5 years ago. I put her away and hadn't replaced the foot pedal until this summer, but I use her a lot now. Her serial number dates to 1948, which incidentally is the same year my mama was born.
I have more (99k, 66 "red eye," 127 "Tiffany," White FR, etc.), but these are the ones I've used the most.