WHO KNOWS how long it had been since he was really used, let alone oiled and cleaned. So I got out my trusty (free) manual and read the section on cleaning and oiling the machine.
The manual is very clear that you should never apply oil to the gears of the machine. It says to use lubricant on the gears, NOT oil. I had the standard sewing machine oil but I didn't have the lubricant. I did a search online and there are lots of listings on eBay for old lubricant in old metal tubes. Very cool. But I wanted to do it right away. So I did another search and found out that they sell it at JoAnn's. Easy. I ran and picked up a tube for just a couple dollars.
I laid out all my tools: screwdrivers, cotton swabs, cloths, oil, and lubricant. I was terrified. It seems wrong to have all those gears and private parts exposed. I was worried about messing something up. Or hurting him. Or - worst of all - not being able to get him put back together. So I read the manual again, administered general anaesthetic, and went for it.
I gave him the whole spa treatment: a bath, a cleanse, and good moisturize. There was some surface dirt but he polished up beautifully. I opened him up and brushed out his sensitive areas. There were mounds of lint, grime, and even some straight pins in there. I oiled and lubricated him according to the diagrams and closed him back up.
I gave him a test run and he sewed like a dream. So quiet. So smooth.