A friend of mine has a Bechstein Green Welte upright.  It's tracker bar
has a number of extra holes above and below the row of standard holes,
which suggests that Tom Steuer's guess about one of the tracker bars on
that Steinway may well be correct.

I assume that suction was applied to these extra holes to keep the roll
paper from lifting off the tracker bar, although one would think that
the suction applied to all the non-speaking holes (usually the
majority) would do that; isn't that so?

John Phillips in Hobart Tasmania.