Mine’s a US copy and my guess would be it was just the US as it was a mistake at the pressing plant. Having said that, I’ve got mispressed copies of Let There Be Rock from Australia, Germany and Benelux. They’ve all got cock ups involving AC/DC tracks though and I doubt that two different pressing plants would independently use the pressing plate from a totally different band and purely by chance use the same side of the same album and swap it for the same side of a double album. Too many variables if you ask me.