Yup, kinda look like that..., but not that small...maybe those are just young birds though...My females did come out (as F-1) as auto sexing, like a Silver Cuckoo does, with males (in F-1) as Silver Cuckoo but with golden hackle (like a golden Cuckoo, the Biel and Silver Cuckoo Marans both double barred males) the idea (recipe) is to discard the silver or dark males, and keep the gold-silver (impur) males and rebreed them back to their mothers (in this case the Biels) in the case of Golden Cuckoo, we'd be using Silver Cuckoo marans and Black Copper marans (to supply the gold)
In my case I used Biels to supply the gold.
I really have no energy to keep the recipe going through 4 generations.
I figured after following the recipe through, I'd have Bielefelders...LOL
But I'll look into it further !