William Gibson, Nathaniel Hicks, Farrah B. Long, Samuel McClure, Yancy Roark, and 1st Lt. John P. Starling show up in the Missouri SOS database as Babcoke's Miller County Provisional E.M.M. "Killed Aug. 30th, 1864 by Bushwackers." Stamp on most of the cards say: "From the rolls in Office of Auditor War Dept., Wash. D.C."
Only Richard C. Crisp is missing from the outfit (James L. Crisp shows up though in Babcoke's 1865 VMM, but not killed.)
So it looks like we have narrowed the date of Crabtree's demise somewhat.