In 1848, Mint employees used a single pair of dies to strike a small amount of Proof Large Cents. Those dies were reserved solely for Proofs, and no business strikes followed. Thus, if an 1848 Large Cent can be attributed as a Newcomb 19, it is most definitely a Proof, even if it spent time in circulation. In 1977, Walter Breen enunerated twelve different examples; today, we know of at least the same number of demonstrably different ones, plus a few more. Thus, the number of survivors falls somewhere between a dozen and twenty examples.
Most survivors have toned down to a brown color, with varying traces of original mint red. Technical quality ranges from PR60 to PR66, with most falling between those grades. One of the more exctiing examples is the nearly full Red PCGS PR65CAM (now in the ESM Collection).