A paper attached to the chamfron's box relates to the Tokodo collection. Tsunajiro Ueda, who worked for Tokodo, collected many masterpieces. They are highly prized by collectors and dealers in Japan.
Dr Sasama in his book Nihon no Kacchu Bugu Jiten mentions "Horse Armour was popular in the Azuchi-Momoyama period (1573-1596). It was not expected completely to protect the horse and was heavy. However it had a threatening and dignified appearance in the eyes of one's enemies and so some generals liked to use it and some decorated the armour with peacock feathers, tigers fur, etc."