The exact quote i have is: "Cook, William, Haverhill. Capt Moses McFarland's co., Col John Nixon's regt; receit for advance pay dated Cambridge, June 10, 1775; also, Private, same co and regt.; muster roll dated Aug 1, 1775; enlisted April 24, 1775; service, 3 mos 15 days; also, company return dated Winter Hill, Sept 30, 1775; also, order for bount coat or its equivalant in money dated Winter Hill, Dec 20, 1775; also, Capt McFarland's (7th) co., Col Thomas Nixon's (4th) regiment; receipt for waged for Sept, 1776' also, same co and regt; return dated North Castle, Nov 9, 1776; also, receipt dated Marh 14, 1777 given by Capt McFarland, for wages due said Cook, he being deceased"
It looks like the source information includes at least some muster rolls; and I see that all rolls have been placed online at footnote.com , but the relevant muster rolls don't seem to be there..
As to the other question, no individual has ever applied to DAR for this veteran.