[ Kent Zacherl wrote in 090729 MMDigest --
> Can anyone tell me spacing and hole size of the Castlewood organ
> tracker bar?  It is for my reed organ project.

Sure, Kent.  The Castlewood Organ tracker bar is to the John Smith
music roll standard.  With the music roll playing towards you,
starting from the left (lowest note ) to right (highest note):

  10,9,9,9,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,7 = 140 mm total

There is a hole at each comma.  These are the positions of the hole
centres, so the lowest note is 10 mm from the paper edge and the
highest note is 7 mm from the paper edge. The three lowest holes
are 6 mm diameter and the other 17 are 4 mm diameter.  In practice,
everyone punches 4 mm holes throughout.

Should you have any further queries, I will be delighted to help.

Regards,
Tom Newsome - Castlewood Pipe Organs
Western Australia
http://www.castlewoodorgans.com/