It’s actually an interesting problem, in a despotic anti-constitutional sort of way.
If the coins were issued by the SF Mint (monetized), they were subject to EO 6102 and needed to be turned in. If they were never issued, they are US government property.
Either way, somebody somewhere did something illegal.
A few of the coins from the Saddle Ridge Hoard were actually minted in Georgia, from gold that was found during a gold rush in that state long before the California Gold Rush. Would these Georgia minted coins have been at the San Francisco Mint in 1900?
It appears that EO 6102 (morphed to 6260) was revoked by EO 11825
EO: 6012 made an exception for "gold coins having recognized special value to collectors of rare and unusual coins."