There are several Marans hybrids that different hatcheries are doing. Some name the varieties they are using and some do not.
This is why I made the second post.
Just wanted to add-
Just because he looks similar to the bird in the ad photo doesn't mean that is what he is. He could also simply be an over colored Marans.
No way to tell just by looks.
He is a beautiful rooster either way.
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