He looks like a Dominate Copper. I do believe they are a RIR/Marans mix.
Here is one of several adds online with a photo.
https://jenks-hatchery-inc.myshopify.com/products/dm-z1-gr
Here is one of several adds online with a photo.
https://jenks-hatchery-inc.myshopify.com/products/dm-z1-gr