He could be a Colored Dorking, Sandhill carries those, too. It would be easy to mix those chicks up. This is from their web page:
Colored Dorking
Colored Dorking - Slightly variable in color. Male’s neck and saddle feathers can be silvery to golden straw colored. The remaining feathers are basically black with light straw lacing. Females will vary from silvery to golden straw with varying chest colors. Color variations occur within this variety. They have a single comb with six points.
I think that you are right in your assessment.