The will for John Cosby is on his Wiki page:
https://www.wikitree.com/wiki/Cosby-33
but, it picks up mid-sentence rather than from the beginning of the will -
WILL
to son John Cosby 19 slaves and increase: Tom, Kate, Young Kate, York, George, Dick, Thebe, Sam, Aggy, Robin, Moll, Mingo, Jo., Dinah, Supio, Floro, Hannah, Lucy and Phillise; to my son William Cosby 22 slaves and increase: Old Will, mulatto Will, old Dinah, Matt, Bess, Sue, great Jenney, Dinah, Peter, young Tom, Abram, Jen, Adam, Aggy, Jemmy, Charles, Beck, Peter, Jolly, Bartlet, Milly and Cuzie. To daughter Elizabeth Snelson 8 slaves Sarah, Charles Rodal, Patt, Lot, Amey, Delcia and Pats child; to granddaughter Mary Anderson wife of Benjamin Anderson 2 slaves Ned and Emear; to grandson James Duke 1 Negro Sabry; to Grandson Cosby Duke 1 Negro Michael; to Grandson James Cosby son of James Cosby 1 Negro Pegg; to son John Cosby all my land in Hanover Co. being two plantations containing about 718 acres; To my son William Cosby 1200 acres to be laid off out of my tract of land in Louisa where I possess about 3,000 acres, the same 1200 acres is to be laid off where William now lives and where the quarter is that is called old Wills Quarter. The remainder of the above tract of 3,000 acres in Louisa after this 1200 acres is laid off for son William remainder 1800 acres to my two grandsons Charles Dickenson and Higgason Dickenson sons of Griffith Dickenson to be equally divided between them. to son John Cosby all my personal estate that lies in Hanover Co. To son William Cosby all my personal estate that lies in Louisa Co. to my daughter Elizabeth Snelson 1 Negro Betty. Appoint two friends Clevears Duke and Bartelot Andersons exors. 12 Sep 1760. Sig. John Cosby. Wit. Nathl. Talley, Israel Hood, Garland Anderson. Rec. 26 May 1761 proved by oaths of all the witnesses.[2]