Vertically align bar line in polyphonic music

[Marcel Korpel]

Hi all,

Example at http://pastebin.com/1USBkWCH

I am transcribing a 16th-century mass for 4 voices I got the next
problem: its Kyrie is divided in three parts that are separated by a
|| bar. The last note of each part is a longa (sometimes with a
fermata) that just fills up the rest of the space until all voices
pause. In the upper voices I manually expanded the internal measure
length to fit the longa in one bar (lines 47 and 76). Those voices
look correctly.

As the two lower voices reach the longa at earlier places, I need to
fill the leading space with invisible rests ('s', lines 98 and 118).
In the example the || appears too soon, it needs to be moved to the
end of the measure. But when I fill up the remaining time with 's1 s1'
(just after the single one in line 98, another (normal) bar line is
inserted at the place where the || was. Of course I don't want that
extra bar line to appear.

The question is: what's the best way to fill up that remaining space
in the two lower voices? Or is there a better way to vertically align
the || bar line? At
http://img209.imageshack.us/img209/4620/lilytest.png I uploaded a
mockup of what the score should look like.

Thanks in advance!

Kind regards,
Marcel