I really like this custom a lot too! Thanks for pointing it out, Martin, and thanks for creating it, Gaspodfreud!
As others have written, the heraldry is superb and very authentic. I also like how you've used the blackened armor, which would have been historically correct (e.g. The Black Prince's armor). My only suggestion would be to use the blackened sword from the 4689 Knight Special so that the metals match.