Complex sentence: Aside from the hired Draftsmen, mechanics and journeymen, much of the labour needed was done by the people of the "Passage", these local residents had a reputation of being hired for DND developmental structures and posts.
Split into simpler sentences: Aside from the hired Draftsmen, mechanics and journeymen, much of the labour needed was done by people in the "Passage". These local residents had a reputation of being hired for DND developmental structures and posts.