Gee, why do you think that the government require bullion and coin dealers to obtain the names and addresses of both buyers and sellers?
EVEN WHEN THE BUYER PAYS IN CASH.
I think you can buy/sell
American Gold Eagles for Cash with no paperwork.
BTW, ref my post on using industrial metals instead of gold, I have seen some suspicious activity at scrap dealer yards that look like money laundering for drug dealers. No scrutiny by the Feds.