Hot Rods Mystery Heads - Can anyone identify these things?

Has anyone seen a set of heads like this?
This one has the Detroit crew baffled..............

There are a few casting marks; letters numbers, no branding or words.

 

1947 Rolls Can hardly

 

Looks like the pattern and number of holes for a 24 stud flathead. Can't identify a manufacturer. Someone else here wil be able to zero in on the specifics.

Frank

 

What does the chamber side look like?

 

Photos of that side tomorrow...

 

Look like rough castings that were never finished?