Cleaning cast iron patch on vintage Singer
Serial Number F8045010, can't determine if USA or UK made. I have cleaned the gunk out of interior and bottom, but now ready for topside of machine cleaning. Large patches of flaked off japanning black finish. If I clean the topside now, I understand I need to clean with sewing machine oil all over, especially the decal areas, but - is it OK to go over balded cast iron patches with sew machine oil also? Would that make the cast iron patches too oily and resistant to the black shellacking which I believe would be the next step? Am new to forum, will try to load photos. Also on the bobbin winder photo is something missing on the right hand side where the bobbin fits in? Looks like those threads are wanting something on them there. I hope the photos load.
Thankful for help and advice.