The David C. Davis Company of San Francisco became well known for its involvement in the Silver Certificate Redemption Program, working with the Mint Of The United States At San Francsico in the 1960’s. The end of the program on June 24, 1968 was marked with a commerative coin designed by V. M. Hanks, Jr. (ANA 034390) and David C. Davis of San Francisco as a counterpart to the famous $50 gold slug of the California Gold Rush Days.
these commemorative coins are somewhat common, David C Davis Company unique balance scales hallmark on a 5 oz class silver
ingot certainly is not; I have only ever seen two of these in the 5 oz class.
While researching another topic in old Numismatists, I came across the advertisement below. This makes a neat story with a similar ingot in hand!