The 715, 815, HL-722, and HL-822 are all deviations of the same “guts” – each model simply bearing a different cabinet. The service manual and parts are the same for all four models.
This model was designed to be used on 2 channel organs, with the appropriate console connector kit.
The 715 is a high power cabinet with a normal Rotosonic drum and horn in it’s rotary channel, and a two way full range stationary channel with 6×9 speakers firing from the left side, right side, and front of the cabinet.