In response to John Farrell's request about doing damage using the
vacuum cleaner to clean the tracker bar, I say the answer is 'no'.
Well, sort of 'no'.  A hand-held old-style tracker bar pump might even
put more pressure on the leather pouches than a handy Hoover, which
is actually more gentle.

The one thing to be very careful about is not to scratch the tracker
bar with the nozzle of the vacuum cleaner.  Therefore, I have rigged a
rubber end to an old-style tracker bar pump to fit the end of the
vacuum cleaner.  Rapidly running it back and forth across the tracker
bar creates pulses that will dislodge lint and dust from the bleeds,
and seems to do a very good job.

In addition, one must not use paste or a liquid type polish on the
tracker bar as eventually it will plug the holes, and also there is
acid in many brass cleaners that can damage a tracker bar.  I suggest
that a tracker bar be polished using cotton wadding type polish such as
Never-Dull, and then finished up with plain soft paper towel.  If you
want a lasting polish, mask off the areas surrounding the tracker bar,
and lightly spray with clear lacquer.   (Yes, they were originally
lacquered.)

Bruce Clark