I'm pretty sure the Double-Duty Surgilator was introduced on the LFA series.
Online parts diagrams show LFA7800, for example, having Double-Duty.
LAA and LDA both do not. My family had an LDA7800 which had a "regular" Surgilator. Neighbors had an LFA7800 that did have a Double-Duty.
LAA7800W4 Agitator
LDA7800W3 Agitator
LFA7800W0 Agitator