There were a few hired, but mostly when Junior wasn't watching and Della was out of town. Pussy Galore comes to mind in the early 80's, Seth Efrican maybe, husband was also a pilot and/or engineer?
What happened to Sam's father, Dave? Is he still in PNG - last I heard I think he was with Pacific Helicopters?
I lived next to the Wriggles in the Stone Houses, 1970s.