couple thoughts. The darning foot (used for free motion) ha been around for a long time. It was used to darn socks and holes in clothing. I took a clas years ago and was shown a beautiful heiroom childs dress with cutwork that had been done on an old machine.
Having said that.
Your machine is most likely a low shank machine.
Check for a "Big Foot" available from Lynn Graves. I believe she developed this foot to do free motion on a Singer featherweight. Also. Search for a group intereted in vintage machines. They will most likely have good information. You might email Lynn Graves and ask her the quetion.