The 1857 Half Cent is one of the more common dates in Proof, though our original estimate of the existing population at 250+ seems a bit high and I may revise that figure downward in the future as more data comes in. Probably, 100-150 is a better estimate.
Proof 1857 Half Cents can be found with Heavy Dates and Light Dates. Heavy Dates have strongly impressed digits, while Light Dates are shallow and spindlier. Dannreuther believes this was caused by a lapping of the dies, but positional differences may indicate two different obverse dies. Either way, it appears Mint employees struck Proof 1857 Half Cents on more than one occasion.
The majority of existing Proofs are PR64BN, with but a few examples better. Red & Brown Proofs are very rare, and Red examples may not exist.
Howard Rounds Newcomb (valued by Newcomb at $5), sold privately in 1935 - B. Max Mehl, sold privately in 1935 - Col. E. H. R. Green Collection (appraised by F. C. C. Boyd for the Green Estate at $1 on 8/9/1937), sold in 4/1943 for $1.25 - Partnership of Eric P. Newman & Burdette G. Johnson (St. Louis Stamp & Coin Co.) - Eric P. Newman Collection - Eric P. Newman Numismatic Education Society - Missouri Cabinet (Mocab 57.2.2) - Goldbergs 1/2014:227, $9,487.50