I have decided to model the herald for the Lord of Gruthuyse(e), a Flemish noble. A picture in my book "Heraldry"" has a caption identifying the Lord of Gruthuyse herald as wearing a tabard with his coat of arms (black cross on gold field, crossed with a gold saltire cross on red field) and is active in tournament jousting.
I believe that the noble is Louis de Gruuthuse, who has the same coat of arms, and is very successful in tournament jousting.
https://en.wikipedia.org/wiki/Louis_de_Gruuthuse.
I sculpted the outlines of the tabard over the formed arms. Notice that I create a very basic armatureto capture the pose and anatomy, and then improve on the details later.