The Hammond Organ, Part II

(con't from Part I)
History has shown that the Hammond B-3 (photo) console organ was the most popular and most widely used among the older Hammond models.
In this photo the bottom octave preset keys are visible in reversed colors on both the Swell (upper) and Great (lower) manuals; these have a locking spring action when depressed to indicate that they are engaged; they may be released, or cancelled, at any time by depressing the (black) low C preset key.
Closer examination reveals that both the A# and B preset keys on the Swell manual have been depressed two-at-a-time, allowing both banks of Swell harmonic drawbars visible above the top manual to sound together.
(con't in Part III)