Not hundreds but THOUSANDS in pits in the Australian Outback. There are many theories why they were buried. The leadings ones are.
* The then Aussie govt didn't want to sell them surplus for fear they would be smuggled into other countries.
* They were in such poor condition, they couldn't be salvaged or sold are surplus.
* The British motorcycle industry wanted to sell into Australia after the war. Thus, they wanted these American Harley's out of circulation to make market demand.
* They could not sell them and was required to ship them back to the States. The cost of shipping was too much so they "lost" them by burying them in the Outback.
This is one of those things talked over beers at Sturgis ever year at some bar somewhere.