Yes it was. So let the law play out.
Statute of Limitations, BTW, refers to criminal liability, not transfer of property rights. I believe that even if I hide my ill-gotten gains till after the SoL runs out, I still don’t have a legal right to the property I stole.
The relevant law here is probably that regarding “treasure trove,” which goes in the common law all the way back to pre-Norman times in England. Under common law the sovereign owned the rights to ALL treasure trove in the land.
Sovereign rights transferred to each state at independence, so in some states common law still applies. Most have, however, modified common law by statute. Various states assign property rights in treasure trove to the finder, the landowner, the state, the county, or the township. Or split it up among these various entities in different ways.
No idea how CA law applies specifically, or whether federal law trumps if the coins were originally federal property, which is likely.
Should have melted it down