According to the study done by the late Howard Madaus, the only ANV flags with Gettysburg honors were those issued to Ed Johnson's Division (who did not get new ANV flags before the GB Campaign due to a wool bunting shortage at the Richmond Depot) and those units of Heth's Division that lost them at GB. The 21st VA was in Johnson's Division as was the 48th VA (same brigade infact). The Montague invoice was indeed for flags for Heth's Division. I have not found one for Johnson's.

Greg Biggs