How to clean a vintage presser foot?
I now have a Singer #161612 Special Purpose presser foot to fit my 252 machine. It is in excellent condition except there is a tiny blob of black "gunk" on the inside edge of the "ankle" or "attachment area."
I prodded it with the tip of a stylus. It has the texture of melted rubber. It does not seem to be time-hardened oil; it is jet black and rubbery. The spot is about 1/8" x 1/16" or less.
The darling little foot, made in Great Britain, seems to be made of stainless steel; would this be correct? A magnet sticks to it at both the foot and attachment areas.
What would be the best way to remove this gunk without harming the foot's finish?
The actual foot area, (the sole?), is made of very thin metal. The top part (name?) that attaches to the presser bar is thick, solid, and hefty.