[Son of Númenor]

Gandalf 'died' on the 25th of January and was brought to Lothlórien by Gwaihir on the 17th of February. Assuming Gandalf was reborn on the day that Gwaihir bore him to Caras Galadhon, his 'reformation' took a grand total of twenty-three days.

But I'm guessing that was more of a rhetorical question, Bêthberry.

Gollem observes "Yes, He has only four on the Black Hand, but they are enough."

Could Sauron not reproduce the finger that was lost? Could he have been eliminated, um, piecemeal?

It can be argued both ways. If "the Black Hand" is a metaphor (exempli gratia "The Yellow Face" & "The White Face"), then the 'four fingers' is also a metaphor - for the literal loss of a finger in his previous incarnation, and for the loss of the Ring. If it is not, then Tolkien is implying that Gollum has come into contact with a physical manifestation of Sauron. The latter seems less likely to me.

Now I will my attempt to answer the question with a few questions of my own (I have been doing it alot lately): How would Gollum have known that Sauron lost a finger to begin with? and why should we trust what that Stinker says anyway?