A friend recieved a box of feet and machine accessories from a home ec dept. shutting down. They might all go to a singer - the throat plate says 171137 singer U.S.A. on it, and the large whatever-it-is foot says 161420 singer GT BRIT - but some of them might go to something else. All the smaller things don't have any maker marks.
Can anyone help me identify what these do, and are they worth anything?