I bought a couple of wooden office chairs at a thrift store last year for $5.  That's for both.  $2.50 each.  So of course I could not pass them up.  I got them home, moved them around the garage for a year and finally got to work on one.  I know at one time I have a before picture, a sanded and possibly one other progress picture, but I have sense lost them.  However, the other chair was in roughly the same condition, so it is here to give you some idea.

I started by disassembling the whole chair.  Every piece I could take apart, I did.  I sanded all the pieces which was the most time consuming since I have to take off layers of varnish and stain.  I reassembled the chair, stained and finished with three coats of clear.  With the metal parts, I degreased, scrubbed, reassembled and reoiled.  The only thing about the chair is that the shaft wobbles a bit.  I think there may be a wedge or something missing.  Overall, I am very pleased with the way it turned out.