A super image! As a non-comm, his momma probably made his outfit, and likely used her own idea of pattern and trim. Let's give her a break for the fine effort.....................
There is actually no existing evidence that he was a 1st Sgt, though he was known to enlist as a private, promoted to corporal of Co A, then Lt. and 1st Lt of Co K, finally promoted to Captain of K in 1864 going AWOL Feb of 1865.
I have to imagine the records are lacking and he had to be promoted at some juncture to Sgt prior to his Lieutenancy.