Here is the Severns reference that you are looking for. It is for Gower Sovereign and 4 ch.
Source: The military papers of Colonel Henry BOUQUET microfilm: Brigadier-General in America, Lieutenant-Colonel of the Royal American Regiment 1754-65. Edited by S.K. STEVENS, Donald R. KENT & Autumn L. LEONARD. London, England: World Microfilms Publications 1978. British Musuem's Additional Manuscript 216545, reel 16. Thanks to William KINCAID for sending in this list!
A List Of Prisoners at the Lower Shawana Town: Robert PUZY/ John (POTH)/ John C(eller)/ Samuel HU(ss)/ Abraham (OR) mand/ John FREELANDS & 3 ch. & wife/ David CO(ur)DAY/ Jacob GOOD/ Dutch JOHN/ Thomas CABE/ Gower SOVEREIGN & 4 ch./ Margrett BARD & 5 ch./ Mary OR(inger) & 2 ch./ Dutch Sar(r)ah & 3 ch./ Sa(rr)ah BARNETT & 1 ch./ Vanny BARNETT & 5 ch./ (A)lley CINCADE & 3 ch./ Mary BURK & 2 ch./ Betsey ROBERTSON/ Hannah DENSY/ Betsey SNODGRASS/ Betsey MEDLEY/ A Dutch Girl/ Nan(s)ey MILLER/ Betsey JAMISON/ Mely FULLERTON/ Mary MOORE/ Susanna VOSS/ Molly GOULD/ Jean MACRAKIN & her sister.
Carried Up: Ann (FOLKISON)/ Wm MEDLEY/ Nansey RANICK, her sister & 4 brothers/ James STEWART/ John GUTHREY/ Le(zy) BENGIMAN/ John MARTIN/ Willm DAYS/ Benjamin ROBERTSON's son/ (Lo)dick/ Solomon CARPENTER/ Margrett CARPMILL/ Saley BOYLES & brother/ Joseph RAMSEY/ Molly CRISTOPHER/ Molly MOORE
Colonel BOUQUET, Comandant, Fort Pitt
Gower Severns had land on Beech Fork of Salt River near Davis' Station
Here are few more references to him that I have found
There is a Gawer Soverins listed next to John Soverins in book listing land grants: Old Kentucky Entries and Deeds; Jefferson Entries; page 289 for 400 acres on 2-21-1780 and 1,000 acres on 6-24-1780; both on Beech Fk. "In 1785, Linn (Benjamin Lynn) acquired a patent to one thousand acres of land on the south side of the Beech Fork of Salt River, six miles southwest of Bardstown (Kentucky), a tract to which he had previously purchased a pre-emption right from his brother-in-law, Gower Severns. "
From Nelson county Deeds book two P 2612 August 1788 James Davis, wife Hannah to John Reed, 20 pounds, 400 acs., waters of Beech Fork adj Gowin Severn's near Davis Station.
From Nelson county Deeds book four 10 August 1790 -Samuel Ray, wife Mary, to Edward William, 100 pounds, 300 ac. south side of Beech Fork, adj. John Leaucaus, John Richey, Abraham Hornback, Benjamin Lynn, Frances McBride, Ebenezer Miller, James Fanuel, and Gower Severns.