Did you check the GAC website? There must be a pphone number there somewhere. This close to the event, calling someone associated, is going to be your best option. I would guess you'd have to go by the rules they have set on the website as a general guidline but, yours is a more special impression.
Contact via mail or phone:
"Grumpy" Dave T.
"Yet, despite these small numbers, Kernstown was one of the most decisive engagements of the war. The Confederates, Under Jackson, though soundly defeated, ultimately lost the most. As historian Bruce Catton observed: ‘The victory meant nothing at all, whereas the mere fact that the battle had been fought meant a great deal.’ Indeed, the ramifications of this odd little affair reached all the way to President Lincoln."