Just dropped into Max's to check out some carrier track. The Australian (and NZ) track uses a different method to retain the link pins. The pin is pushed through the holes drilled into the cast track links and secured with a lead plug which is driven in after the pin and expands. As this plug has to be inserted from the outboard side of the carrier track, the castings are machined as left and right peices. In the pic below, the three links on the left of the pic have the lead plug in place, the next has no plug and shows the small hole which prevents the pin passing straight through, this would be on the inner side of the track.The last link on the right has no plug and is from the opposite track and shows the large hole which accepts the pin and plug. These must be machined as Left and Right track pieces, but which is which is the mystery to be solved!
: It may just be an optical illusion, but Max and I believe the horns standing up are symmetrical and not cast leaning one way or the other. They just look out of alignment in the pic.