A box of matches
It had to be a box of Federal matches, the ones that were made of thin wood. Their three dimensions measured exactly 10, 20 and 30 nautical miles on a WAC, which in a PA24 @ 150 kt was exactly 4, 8 and 12 minutes, plus/minus 10% for head/tailwinds.
Alex McKenzie was a superstar FSO - I was arriving "night VMC" one night and told him I was making a practice NDB approach. He rogered that and told me the A/NSW Fokker had just mate three practice NDB approaches and was now carrying out a practice diversion to Orange. He added that "visibility appears to be pretty good over the town though."
The Hungarian migrants were all landed at Wagga, not Albury, which only had about a 500m grass strip at that time. I was in the RAAF at Wagga at the time and they were all flown in by Flying Tiger and UTA in DC-4s with 85 pax in an aeroplane normally configured for for 52. They were bussed to Bonagilla near Wodonga. Peter Abeles was one of the migrants. One flight arrived from Darwin on 3 engines - had been observed feathering one shortly after takeoff from Darwin and was running 60 minutes late at Wagga where he found he also had a flat nosewheel tyre. A couple of times thay got the RAAF fire tender to park under the rear fuselage with a matress so they wouldn't fall on their tails when they powered off.
Ooops, I just scrolled down the other posts and found somebody else's account of the matchbox trick. I'll never forget the looks on a Qantas crew's faces at Sydney briefing when they looked curiously over my shoulder and had the matchbox trick explained to them.