As many Aussies know, these boxes often sat behind Holden V8s, sixes, Ford V8 and sixes as well
they are a buttery box specially the rare crown and celica gt version supposedly use porsche synchros.
Toyota built the best boxes, Nissan and Honda engines while mitsu did both well just smaller pockets.

Here in japan I can find the W50 easy enough as they are considered heavy at 40kg
but really just lighter and stronger than most 72 series Nissan boxes.
Get them while you can.