Here you have a proof or essay Mexico 1000 Peso banknote that is unlisted in any reference work that we are familiar with. It portrays the mythical Native American ruler Guauhtemoc in an oval frame surrounded by very ornate engraving courtesy of American Bank Note Co.

Unlike a Specimen this note has no serial number, a triple width left margin with registration marks, and 2 red Bank of Mexico seals on an otherwise blank back.  A most unusual and no doubt very rare currency discovery possible worth $1000's. Merits further research...

Never circulated of course as it is not an issued note!