I dug through my box of feet and found two that look like the ones on Nancy's Notions. Mine are Japanese made, but do not look like junk. I thought they were Singer parts until I used my jewelers loop to read what is on them.
Unlike the modern made presser feet, these are all steel.
On the top of the presser foot bar side of the ankle they are marked with an "L" over the word "Japan".
The on the inside of the top of the foot it's marked: US PAT. 3512490, under that; OTHER PATS. PENDG.
I haven't used them yet, but will do so soon.
Joe