The only machine I've heard if as being "Rare" is the National Two Spool Machine. Just the cannister for the spool of bobbin thread, that cannister, had a beginning price of $350.00 pm E-Bay a while back! I told my son, let's make real sure our cannister and any other parts are in a secure container and will not leave this house! I am sorry that you are facing such a project when you're really not "into" quilting and sewing machines! I am still looking for an inexpensive (HA!) Featherweight for my cousin in Oklahoma. I have a very limited budget, but I would surely like to find one for her.
Jeanette