Hi guys, K is the man, but as there is no answer yet, if I am not wrong, red boards appeared around or along with Khartago, so red boards if I am not wrong date back to the Khartago launch time.
I get two of the first Khartagos, from production line and they already sported the red board.
When was it ? I do not remember, but you can search when Khartago was launched and figure out.