This variety was long assumed by Breen (1988) and Snow (1992) to be an overdate with repunching. However, research by two-cent specialist Frank Leone and members of the Fly-in Club revealed that some 1865 digit punches were cast with a 4 underlying the 5 (Longacre’s Ledger Vol. 2, No. 2). Therefore the 5/4 existed on the digit punch itself.
Digit punches are made similarly to dies. Like a hub, which creates dies, a matrix is used to create digit punches for any given year. If there is a flaw in the matrix, then that flaw will be transferred to each digit punch that is made from that matrix. It is possible that the mint ground away the 1864 from an existing matrix for reuse in 1865, but unintentionally left traces of the 4 in the matrix.
The 5/4 seen in the 1865 PUN-001 and PUN-002 are also seen on several different dies in the two cent series. The 4 underlying the 5 is always in the same exact position on each die, despite the date positions being different for each. This leads us to conclude that the 5/4 could only have been imparted by the use of a single, flawed digit punch and is not an overdate.