Miriam I'm pretty sure I'm the wrong guy for a tuturial on these old machines. You're one of the people here that I go to when I'm looking for answers. Until less than a month ago I've never even looked inside a sewing machine. They are much like any other machine though. Rust removal, cleaning and proper lubrication does wonders for them.
If I drag one home in bad enough shape I might do more than just the maintenace ths one is getting. Right now though all the 101 needs is a little attention. It already spins more freely than before.
One thing to keep in mind is grease and oil breaks down over time. Oil turns into a varnish like substance and grease breaks down into a wax or soap type of stuff and they lose their ability to lubricate. Even unused grease breaks down over time so after twenty years or so the older singer grease will no longer be as effective as when it was new. This is true even for unused sealed bearings. They only have a life expectancy of about 20 years whether you use them or not. I'm not an expert so I don't know if that also applies to sealed tubes but once the grease is exposed to air it will start breaking down.
Rodney