LavenderBlue,
I can imagine our foremothers oiling the machines very often. Just not cleaning the old oil away. I can't count how many machines I've cleaned that had layer after layer of solidified oil on every part of the machine. The only parts that were clean were the outside where the fabric touched the machine. Inside, underneath was a gummy, varnished mess.
Last year I cleaned a Singer 127 that was so bad I had to use gun cleaning solvent to clean it. Regular oil, kerosene, Tri-Flow, wouldn't touch it. So I cleaned it the first time with gun solvent, then cleaned that off with denatured alcohol.
Yep, our foremothers were oiling fiends. My mother was that's for sure. My avatar pic is her old HOTHER SEW MATIC 15 clone. She had it for as long as I can remember (I'm 62 next month) and only retired it when she "moved up" to a ZZ machine. I still use the HOTHER. It runs just fine, she always kept it oiled.
Joe