1921 Proofs were made at the insistence of notable numismatist Farran Zerbe. Some 78 of these coins have been certified by PCGS, and as many as 200 may have been made.
This subject has always contained some level of VAM controversy, but as of late 2008, the proof can be identified by a small die scratch from the second U in UNUM to the denticles. The Zerbe Proof has 17 berries in the wreath on the reverse.
Similar coins were made for circulation. These "SO-CALLED ZERBE DIE" coins do not have the mark at UNUM.
1921-P VAM-1 is the "SO-CALLED ZERBE DIE" variety.
Please see the 1921-P VAM-47 listing for more information.
Additionally. a second proof variety was struck. The second Proof version is the so-called "Chapman" Proof, named after the Philadelphia coin dealer, Henry Chapman. PCGS has certified 40 examples. "Chapman" Proofs have been listed as having only 16 berries in the wreath on the reverse, but examination will reveal that they are also a product of the D1 or 17 berry hub. Several examples of certified Chapman Proofs may be found in the Heritage Permanent Auction Archives. Please see Lot 2192 Auction 434, 9 May 2007 St. Louis Central States show for a Proof 65 NGC example. The D1 reverse is clearly visible. The Heritage archives also picture Lot 5399 Auction 414, 13 Aug 2006 Denver ANA show, a Proof 60 PCGS example that shows two of the reverse die markers cited by Walter Breen. The diagonal line from the left side of the upright of the I in AMERICA and a short dash in the field between the right star and wreath touching neither are visible in the large image. Curiously, Breen appears to be the source of the misattribution of the hub type. Chapman proofs are of a far superior quality than the Zerbe strikings. Many experts do not consider the Zerbe pieces as proofs, but no such controversy surrounds the Chapman issue.
Additional information on 17 berry reverse 21-P Morgans can be found by clicking the link in this sentence.
Finally, in 2008 Jack Lee discovered that the 1921-P proof coin in the Smithsonian Collection has a 16 berry reverse (D2). It is unknown at this time, and may never be known, the how and why of the production of this coin. This variety is listed for scribbles as the 1921-P VAM-3BV from a circulation strike example.
Soon thereafter in January 2009 at the VAM Thing at FUN, Ash Harrison noted his research on the "true" Zerbe dies. He determined that the same variety tended to occupy PCGS and NGC holders labeled as Zerbe proofs. He also found this variety in some, but not all, other TPG holders labeled as Zerbe proofs. Although Ash did not make this assertion lightly, he was careful to acknowledge that we will perhaps never know the answer with 100% certainty. This variety was listed for scribbles as the 1921-P VAM-1AG.
Please click this link for the full VAMworld.com definitions page.