Technical cast iron nailhead headers/manifolds

I've searched and don't find anything. Anyone know what these headers/manifolds are?

 

Not a clue. They’re not Skylark, not Rivvy? Uhhh?

 

Fenton made cast iron headers for flatheads, and Y-blocks, and maybe they made them for other engines as well? But those don't look very "Fentony".

 

Maybe one of the great big Chevrolet trucks .. they sure aren't headers ...

 

Maybe someone on the Saturday crew knows???

 

I have had several nailheads and never saw those. Pretty bitchin though