Electro-pneumatic and electric-actions
At the present time, relatively few organs with electro-pneumatic or electric action are regarded as historic. However, the mechanism of some instruments may now have historic value as examples of early electrical engineering, and specialist advice should be sought before discarding magnets and switchgear made before 1925.
Stop and combination action
Stop and combination action should be restored without change to its original mode of operation. The type of stop and combination action has a profound effect on the way an organ is played. A simple stop action, or the absence of any combination action, will prevent anachronistic quick changes from one registration to another, and the retention and restoration of an original stop action will help ensure that the instrument is used as the maker envisaged.