FWIW I bought two bars in late 2016 and immediately I got them they were clearly fake - I could tell without taking them out of the seals as they were far too thick to be a bar. The serial number was also a little suspicious as it was too cute but each bar was different.
The seller was nice enough of it but I think he took a bath because he bought it such a long time before that he couldn't get his money back.
If you do not buy from an absolutely top professional dealer such as a mint or some of the absolute best people on
ebay you are likely to get into potential trouble.
here are the pictures sorry for the poor quality - that was just to demonstrate to
ebay that they were fake.



By the way, I ended up sending a very strongly worded letter to the
Perth Mint because they had been giving dimensions of their 1 oz bars that were clearly wrong - taking the maximum length, width, and thickness of all the bars they do and putting them as the maximal dimensions. However if you had a bar with all dimensions at maximal it would be a 3oz bar.
They changed their website specs a bit because of that but not quite to my satisfaction.
This was quite a nice fake by eye as long as you didn't look at the thickness,,, it was clearly a very well plated brass bar - in the packaging it looks pretty convincing if you don't notice the thickness so worth being careful.
A good seller will show all three dimensions of the bar if they are careful - that doesn't mean someone who doesn't show that isn't honest, they just probably haven't thought about fakes that much and may not be as experienced. I am very convinced the person who sold me the fakes just didn't have enough experience to know the issues but he was also a top
ebay seller - not all top sellers are experts in every single thing they sell - they might be coin experts but have little experience with bars for example.