I almost had the same problem as Eliyahu Shahar described in yester-
day's MMD.  A friend asked me to find an action for his gutted Duo-Art.
I didn't find an action that would fit in his budget.  So I never
started it, but I did however collect some information on how to do the
job.

The main answer is "Do it the way Aeolian would have done it."  Of
course it's hard to tell how Aeolian would have done it, unless you
have access to some stacks Aeolian actually did remodel.  If it's only
the position of a few pneumatics at the bass/mid-treble split points
that need to be rerouted, I don't think it's a problem to fill up the
channels with a wooden dowel and drill new channels.  But perhaps
others think different about this.

Personally, I find changing a stack in a way most faithful to the
original, so that it can play again, a better option than to let it sit
in the garage in its original state until it rots away.

Regards from the Netherlands,
Niels Berkers (going to get a PEDA Steck upright Nov. 17th)