all wool and a yard wide Genuine, authentic, bona fide; sincere, trustworthy, straightforward. Apparently the term was an early sales pitch used by yard goods merchants confronted with wary buyers. The earliest known print citation applying the phrase figuratively is from George W. Peck:

hallmark A mark or stamp of superior quality or genuineness; a distinctive characteristic or feature, a trademark. The term takes its name from Goldsmiths’ Hall in London where Goldsmiths’ Company stamped its gold and silver pieces with an official plate mark indicating their grade of purity. Eventually the literal meaning of hallmark ‘a symbol of the standard of quality of precious metals’ became generalized so that it now represents any mark of excellence or distinguishing characteristic. Literal use of the term dates from the early 18th century while figurative use dates from the latter half of the 19th century.

the real McCoy Genuine, authentic; unadulterated, uncut; hence, excellent, of superior quality. Numerous attempts to account for the term’s origin testify to the failure of any to be convincing. Among the more popular are those relating the phrase to a boxer, Kid McCoy, a former welterweight champion (1898-1900). These vary from simple transference by association (the champion is “the best,” superior) to the hypothetical existence of a lesser pugilist with the same surname; to clearly apocryphal anecdotes concerning Kid McCoy’s barroom exploits. It does seem certain, however, that this American colloquialism did come into usage shortly after his championship fame, and that it gained frequency during Prohibition when it described genuine, uncut whiskey. Stuart Berg Flexner (I Hear America Talking) conjectures the existence of a McCoy brand, since the clear McCoy was in use by 1908 to describe good whiskey. The real McCoy remains one of our most popular and puzzling picturesque phrases. During the strike of bagel bakers in December, 1951, a New York Times article said:

simon-pure Real, veritable, authentic; as a noun, the genuine article. In Susannah Centlivre’s comedie play, A Bold Strike For a Wife (1718), Simon Pure was a Quaker who was temporarily impersonated by Colonel Feignwell. When Feignwell had won the hand of Miss Lovely, Simon returned and, after much difficulty, proved that he was, in fact, the real Simon Pure and that Feignwell was the actual imposter.