Try density then. Density of pure silver is 10.5 g/mL. That is, if you're willing to submerge your coin...
If you do submerge it, do it in distilled water so no trace chemicals used to purify tap water mess with it.
I don't see anything that raises red flags for being fake - but it has been so harshly cleaned and polished that it's hard to see what might have been there originally.
Hey, it was only 8200 and change when it was sold in '12 at the Heritage auction... and it's for sale BIN at 22k... (look it up!)
Often when these coins are heavily cleaned/polished, it is to hide alterations i.e. added MM, altered date etc.
Except a Morgan dollar is 90% or 'coin silver' which is only .900 fine and not pure. The specific gravity should be around 10.334 g/cm³ in the case of OP's coin.
Mine? It isn't for sale. It is in a safe deposit box right now. If I were selling it, I don't think I would be asking 22k for it.