Sorry I dont mean to intrude...
The Milton Guards would have had a 1st National aka a Stars and Bars flag early on ...as opposed to the square battleflag that Richmond provide to units as the war progressed..
I believe the flag of the 26th Georgia Infantry still exists. You can google a picture of it...it MAY have been what the 38th's looked like...as they were also in Gordon's Georgia brigade.
For more possible help I recomend that you write to Mark Houseman as he has studied the 38th Georgia for a long time. He may have some insight on this.