The problem with something like this is you are comparing the coins to ONE known counterfeit. If say there were a dozen people making counterfeits, just because your coin doesn't match that one fake doesn't guarantee it is genuine. You could be comparing one producers fake against another and of course they wouldn't match.
I know your business ideals and have said here before that you are one of the few folks I would buy a thousand dollar coin from sight unseen. Having said that, I am certainly not an expert on counterfeit diagnostics but I have traded in my fair share of St. Gaudens double eagles in my day. I would have absolutely purchased that one feeling confident in its authenticity. I know some of the gold counterfeits are pretty convincing but I would be surprised to find this one was not authentic.
Cogent point. Another sobering thought...the TPGs certify fakes occasionally too...although, to be fair, that is always gonna be the exception rather than the rule...for Saints, they really need to know their stuff and earn their money the hard way when they get it right...Spark
They have graded millions of them, so they have a great grasp on what authentic coins should look like. The counterfeits would stick out like a sore thumb
The Micro-O counterfeit Morgans come to mind. I collect them, especially in top tier TPG holders - they were good enough to fool the experts for a long time.
I got to handle about a dozen in the ANA’s “black cabinet”. The tells I use are: 1. Shallowness of Liberty’s hair That's the first thing that caught my eye about the Op's coin... looks very weakly struck/shallow, and not the typical look for a 1924 Philly $20 Lib.