Nice looking console! That's more or less the same as the organ I recently obtained, except for the "-3" in the model number, which indicates that it has the "second church" stoplist. This revision of the standard stoplist has its pros and cons. Worst change is the deletion of the Tierce from the swell to make room for a second Salicional. The rest of the changes are innocuous and have to do with slightly different ratios between the 8' and 4' members of the choruses.
Obviously it MUST have external amps and speakers. The 603 doesn't have room in the console for any amps at all, so there would be a rack with at least four amps, and probably five. There would be at least four speaker cabinets. During the time of the 603, some organs were shipped with HC-type sealed box speakers, while others were equipped with the open-back type 16 on the main channels and the open-back two-box system called the 32A/B on the flute/pedal channels. If there was a subwoofer option, it would be an HC-20.