The 1904 Liberty Head Nickel in Proof is a common coin thanks to a relatively high mintage of over 1,800 coins. Many of the Proofs went into collections and dealer inventories and, for the most part, were cared for well over the ensuing years. Among the Proofs graded by PCGS, the majority are in PR64 or better condition. Also, it should be pointed out that PCGS has certified nearly a third of all the 1904 Proof all by itself.
Because of changes made in the early 20th century in the way Proofs were made, it is difficult to obtain Cameo examples of this date. Deep Cameo examples may not exist or, if they do, they are exceedingly rare. Even regular Cameo examples are rare.
As with most of the Liberty Head Nickels, be they Mint State or Proof, look for well-struck examples that are as free of carbon spots as possible.