You know, I have a vintage Singer treadle machine in my living room. Bought it in an antique store about 15 years ago on the west coast of FL. I haven't taken the time to open her up and see what kind she is now that I know I can get the serial number and find out. I think I will put this on my list of things to do this weekend. Stay tuned, I will post pictures and let you all know what I find out.
I know she works, but needs a spindle for the thread.