In surfing around in images on google I came across this .It tells you what you are quetioning and more about which vintage Singer is best in her opinion for FMQ. Put the follo9wing in google and it should come up for you. I just googled it myself and it comes up as eBay Guides Free Motion Quilting with vintage singer sewing machines click on that and it is what I have listed below. It's Excellent. Do read before you decide.
Free Motion Quilting with Vintage Singer Sewing Machine
by: karenquiltstexas