Re, flaccid arm rest:

  Knock the roll pin out, remove arm rest, use loctite on the allen
screws on the arbor it's attached to.  Open split in roll pin if
necessary to prevent it working its way back out.  Be careful to
reassemble correctly, you can get the arm 180 degrees cockeyed, and
your elbow won't bend that way for sure.

  This job takes 3 hands, but can be done by oneself if your
vocabulary of curses is adequate.

George/ATL