Philadelphia - The 1956 Ingot
The United States Mint Philadelphia silver ingot No. 102, 15.32 ozs with no Melt number is the only known example dated 1956. A ten year gap exists between this ingot and the other dated ingots produced by the United States Mint Philadelphia; and then nothing again until 1960.
Even though this ingot appears to be a remnant of some larger ingot at one time, the serial number, year and weight are all placed within the limits of the remaining obverse and reverse surfaces. Additionally, in both the serial number and the weight, letters and numbers match other United States Mint Philadelphia stampings; the number one used in the serial number and weight is unique to these ingots with the unique lower leg and the ozs matches as well.
As already mentioned, on the reverse, the weight stamping is placed perfectly within the smooth surface of the remnant. This all tells me that if the ingot was cut from a larger example, it was done by the United States Mint Philadelphia and restamped after with United States Government dies.