Reference and example for the harness, saddle and cover of this horse was the movie Robin Hood from director Ridley Scott (2010).
We looked about original pictures from this movie and combined a original Lone Ranger breast harness and a BIG JIM coach horse harness so far.
The result is not perfect, but it has more an ancient look from the middle ages, than BIG JIM cowboy saddles and other BIG JIM horse equipment, which were more in a Western-style.
In the last picture of the gallery you see the Custom Robin Hood on horse.
You find more pictures of this set in
Customs > Historical Heroes > Robin Hood