Another thing with the copies, is that they were artificially aged, so they will be a yellow-brown shade, or more brownish looking, and often are very rigid and crisp- almost seems they were soaked with tea leaves. Besides the cereal box promotion (think was cheerios), they were sold in packs of 5 or more in souvenir shops (i think they are still producing them for sale in shops/online). I am fairly certain these had the word ‘copy’ on them somewhere, and of course they also had the distinctive very dark facsimile signatures/dating. Although some inks can remain dark after many years, if you compare a copy with a real note, there are differences that should be noticeable- such as the copy with the portions that should be hand-inked, everything will look a solid dark shade overall. The original will have more of an uneven look with main inked lettering/numerals darker, but sort of gradually fading into the paper toward termination of pen stroke.
Here is an example of an original as described above (also note the ink used in the inking of the serial number has faded considerably compared to the signatures) ~
https://www.goldeneaglecoin.com/item/5-1863-confederate-note-6th-series-t60-unc
Hope this information is helpful toward future identification