You might want to go ahead and contact the National Archives to see if there is a pension file. If Denezet had a wife, then she probably filed for a widow's pension. In which case, there were probably affidavits filed by Denezet's comrades, attesting to his service, and to how he died. In addition, you might contact the Missouri State Archives and request the muster rolls for the regiment. These are monthly reports, by company, listing all of the soldiers of the unit, including personal information on each soldier. There is a place for comments for each individual soldier, as well as larger section for comments regarding any skirmishes or engagements the unit was involved in for that month. These comments are often pretty detailed, and contain information on engagements found nowhere else in the historical record. In addition, do you have the article "A Chaplain in the 11th Missouri Infantry," by Wayne Calhoun Temple? I'm not sure exactly what it is--apparently a brief article or memoir that was published by the Lincoln Herald, vol. 64 no. 2, Summer 1962.