BCH:
Sure, I'll comment.
I stay out of the 'real' or 'fake' opinion regarding coins, especially cob coins, not because I have little or no knowledge of them, but because I am not an expert nor do I have enough facts.
Of course, if the shield has 3 castles and one lion or the other way around, the 'red flag' flies. And if the coin is overweight, I am suspicious. But if the coin is underweight, no problem. If the coin contains greater fineness than required, I am suspicious; but that is not conclusive since some Potosi coins were 94% fine. And if the coin is less fine than required, that can be no problem, per se. (Potosi coins got down to 79% pure-alloyed with copper, iron or other 'impurities'.) If the coin is 'botched' in many ways, I have no problem--like the recent example of 'flat waves' under a 'waves and columns' coin; no problem. That 'irregularity' occurred naturally in the minting process.
Also, viewing an encapsulated coin or an out of focus coin pic or a viewing a coin's surface distorted by reflecting glare--or other challenges to determining if the coin is real or not--keeps me out of that 'real or fake' arena.
On the other hand, ID--ing a coin as to its age, determining the monarch, chatting about the circumstances surrounding the coin (concurrent with the coin's date events, etc.) and discussing the knowledge that can be learned from the piece (real or fake) is were added value (and my increased attention) exists.
Don........