Can I leave the oiler screw in place?
Now, how do you get greasy fingerprints off the wife's keyboard?
Yep, the oiler screw need not change position. If you wish to play with it, out is more oil, in is less oil. I've forgotten what the standard setting was, but it used to cause jackets to grow black racing stripes up the back left shoulder, very fashionable.
The keyboard: I used acetone, because my wife is a touch typist: now, I can't find the letters on the keys...