These extra holes above the central notes are for the automatic
perforation tracking system that Aeolian in the UK used in the early
'teens.  The slots above the notes sensed the edges of perforations
and were used to operate the tracking system. Paddy Handscombe wrote
a detailed description of it for MMD 20001114:

  http://www.mmdigest.com/Archives/Digests/200011/2000.11.14.09.html

This system was used for a fairly short while -- say 1912 to 1914 give
or take a year or two (my 1913 Steinway has it) -- between the earlier
manual tracking and the familiar twin-ear systems.  It's hard to state
exact dates because WW1 severely interrupted production and lead to
piecemeal completions of earlier part-complete instruments, so it's
hard to be definitive about anything in this era.

Suspicion is that the perforation tracking system didn't work reliably
in practice, and many such instruments with this type of tracker bar
have 2-ear systems fitted, clearly Aeolian work either replacing
unreliable tracking or simply using up the earlier tracker bars.

Julian Dyer