While we are waiting for a photo, I can offer the opinion that a 48-star USA internment flag from the 1920's would be valued on the order of $50 to $100. If the CSA veteran was buried under a CSA flag then the value could be substantially more because of the date of death helping to document the age of the flag. ("Rebel" flags from the mid 20th century are not rare, but they are somewhat harder to find. Wasn't until the Korean war that you saw a lot of Southern Cross flags produced, and the CW Centennial was another occasion that resulted in CS flag repros. So early 20th C CSA flags do have some value.) If the flag (whether US or CS) is made of wool bunting and is free of any moth holes, then you expect the value to be even higher.