San Francisco - 5 oz Class Type I, Medium Font #, w/ Straight Stem Nines
The Type I oval hallmark, medium font serial number with straight stem nines in 999.5 follow next chronologically, based solely on lot number sequence. To date I have found no records to confirm or dispute this placement but my research continues. This series begins with Lot 6 which could carry over from the Type I oval hallmark, large font number with straight stem nines in 999.5 fineness. I have only ever found two of these particular series ingots, both are in the United States Government Silver Ingot Collection of Ken Conaway.
With the change to Lot 7, the Type I oval hallmark, medium font serial number with straight stem nines in 999.5 fineness, start a serial number sequence over. In both Lot 6 and Lot 7 ingots, the weight is always stamped on the reverse and the OZS font is in all capitals throughout.