NCM bars have become harder to find with the vintage silver collector market growing all the time. When I started collecting around 2014-2015 timeframe, these could be found regularly, but no longer. These are really cool bars and use the “Doyle’s” mold, which many collectors look for. They were founded in 1971 in Las Vegas and operated in the early-mid 70’s era.
And below are the 1 oz smalls variety. Note the non hall mark may not be an NCM, but it’s the exact mold and stamp.
Vintage Silver Bars 