From the Heritage Press Release:

A simple memorandum, in three different versions, provides much of what we know about the 1792 half dismes, and yet, it has also been the source of much confusion. The first copy of this memo was discovered by Edward Haden early in 1943 and was brought to the attention of the numismatic world a few weeks later. Shortly after this announcement, Philadelphia numismatist Charles McSorley, Jr., incorrectly identified the author as Jonas R. McClintock.

A second and slightly altered copy of the same memo came into the possession of Walter Breen in the early 1960s, and a third copy was acquired by Carl Herkowitz in 1995. It was this third copy of the memo, also slightly revised, that allowed a positive identification of the author, John A. McAllister, Jr. The earlier attribution of this memo to Jonas McClintock has been continually repeated over the last 60 years, and even today, the misattribution still appears in print.

Herkowitz and coauthor Joel J. Orosz prepared a detailed article around this document, solved its authorship, and answered questions about the history of this famous coinage issue. Their article, "George Washington and America's 'Small Beginning' in Coinage: The Fabled 1792 Half Dismes," appeared in the 2003 edition of American Journal of Numismatics, second series, published by the American Numismatic Society in 2004.

The text of the final version of the McAllister memo reads:

The study by Orosz and Herkowitz provides an in-depth examination of this memorandum, and also looks at much of the history of this issue. In the past, many false and unsubstantiated claims have appeared in print about this coinage issue. Among such claims is one that suggests Martha Washington posed as "Miss Liberty" for the engraver. Another claim that remains unsupported is that the Washingtons provided their family table service for the coinage.

Both of these claims date back to 1860, when James Ross Snowden wrote: "The bust of Liberty is popularly supposed to represent the features of Martha Washington who is said to have sat for the artist while he was designing it ... This piece is said to have been struck from the private plate of Washington, which is not unlikely, considering the great interest which he took in the operations of the infant mint, visiting it frequently, and personally superintending many of its affairs." Today, the numismatic world is indebted to the efforts of Orosz and Herkowitz for correcting many past claims.

Unfortunately, these authors allowed a new and unsubstantiated claim to be introduced. While an entry in Thomas Jefferson's "household account book" dated July 13, 1792, has been known for many years, a related entry dated July 11, 1792 was first published in the Orosz-Herkowitz study. The two entries read:

To view the full lot description, see:1792 H10C Judd-7, Pollock-7, R.4 as a Business Strike(coins.ha.com/c/item.zx?saleNo=1181&lotNo=5570)

Pete Smith forwarded this note about the Cardinal Collection 1792 half disme that was sold by Stack's Bowers on January 24th:

To view the complete Stacks-Bowers lot description, see:Lot #13093. 1792 Half Disme. LM-1, Judd-7, Pollock-7, The Only Known Dies. Rarity-4. MS-68 (NGC).(stacksbowers.com/auctions/auctionlot.aspx?lotid=433604)