I'm fairly certain all the Mazza's were accounted for and located in a warehouse in POM. The story is that the 'guards' removed all the batteries for the usual reasons and all the diesel was drained for stoves and lamps. They were turbo diesel engines and interestingly the vehicles did not comply with Australian regs; rendering exporting to AU unlikely.
PX has made some bad choices of late. Treatment of expat flight crew and engineers aside, the Airbus A220 (nee Bombardier C series) is not the answer for PNG. The country is suited to high wing turbo props and fuselage mounted engines (Fokker etc). Whilst there are a few runways capable of taking the B737 when the runway is not under repair and breaking up, at present I think only POM, Momote and Nadzab/Lae are suitable. Flying the A220 into shorter domestic aerodromes is never guaranteed due to the very low slung engines. Tarmac failures are a feature of PNG, poor repairs, graft and corruption leads to poor rebuilding of runways.
After the A220 is introduced, I'm thinking ingestion of a ground staff member may be on the cards.