I was a 'didiman' in PNG from 1961 to 1970, being located variously at Kerevat, Hagen(Korn Farm), Wabag, Madang,Kar Kar, Aiome, Simbai and Moresby. Also did some flying from 63 to 70.
Always found MAF very good to work with - would always help out by throwing a bag of mail or a ctn of xxxx,(wrapped,of course) in the back of a 185 headed your way. Would always give you a lift out of any odd location if urgent,even if it stretched the 185's loading a bit. What they couldn't fit into a 185 wasn't worth taking! The pilots of those days were bloody legends.
Even during the period 67-70 when I was in Moresby, I can't recall any gripes about pirating charter work being levelled at MAF. In fact, most chtr operators had more than enough work anyway, and MAF always seemed flatout servicing their own strips. Most of which were bloody rough!!
Things must have changed when they set up at Kagamuga in a big way. Pity - they certainly had the right stuff in the 60's.
I read about MAF in the USA not long back. Apparently they run a mountain & bush flying type school deep in the Idaho Rockies, using 180/185. Think it was in/on the international C180 website or in their magazine.
cheers