After James Cawley spent time screen matching the Shatner Kirk tunic, Gerlad Gurian went at the screencaps to try and match the braid. And of course, Gerald, being rather meticulous, did just that.
It is amazing the number of "experts" on Internet forums who have no clue what they are talking about. I am not an expert on TOS costumes, although after the education that James, Gerald and ROger gave me, I certainly know more than most. Still I defer to these guys who have put in the work over years and years. And screencaps don't lie.