The story about converting a T-98 "Green" Welte piano to play "Red"
Welte rolls upset me terribly.  It reminded me of a posting that
someone made asking peoples opinion of removing an Ampico mechanism
from a Mason and Hamlin grand to install it in a Yamaha grand.
(November 2001).

Here, with the Welte, there is an added difficulty due to the roll
width and the direction of travel of the rolls.

My comment:

If you really want to do it, instead of mutilating an instrument,
invest in one of the MIDI players be it PowerRoll or Spencer's Midi-
Valve player.  Re-route the channels as needed an you've got yourself
covered.  I am willing to bet that this is a cheaper alternative than
to redesign your entire world to allow for two rolls to be played, and
you've not _destroyed for all eternity an irreplaceable work of art._

Eli Shahar