From 1987 OHS Handbook:
"Hook & Hastings enlarged the pedal compass and altered the Swell pedal in 1909, and Roy Carlson added an electric-action Mixture to the Great in the 1960's. He also provided new stop labels, many of which do not have the same nomenclature as the originals. Nos. 3-21 of the Great Open Diapason 8' are in the black walnut case; nos. 1 and 2 are inside. The Great Chimney Flute 4', originally named "Flute 4"' on the knob, is indeed a metal chimney flute, as is the Swell Std. Diapason Treble 8'. The Viol D'Amour 8' is a bell gamba and is in the spot where a Trumpet 8' would ordinarily be found, which suggests that one may have been there when the organ was new. The Hautboy 8' (as it was styled originally) is probably a replacement set."