I don't know if this will help as it appears some of the images are missing.
Help needed with Singer 127 bobbin winder The person who posted the images has not been active for a couple of years.
I did one that was super rusty. I soaked it in a solvent that took the paint off. I didn't document doing it. I thought I had taken pictures of it soaking, but have been unable to find them. I do remember it being quite fiddly to get it back together, I also remember that there is a spot where it doesn't make good contact, but I can wind a bobbin.
Janey - Neat people never make the exciting discoveries I do.