Recognize this grain mill head?

I purchased this grain mill head at a yard sale. The seller didn’t know anything about it. It is quite large and heavy, made out of cast aluminum. In the pictures it is resting on the discharge opening, so it is missing the stand and the drive system. It looks very similar to a head for a meat grinder in the way the shaft comes out the back and could slide onto a motor unit.

It has no markings at all, so it is difficult to find more information about it. The opening for the hopper is 8-by-6 inches and the bottom discharge hole is 2-1/4-by-5-1/4 inches, and the whole head stands about 11-1/2 inches tall. The drive shaft is 3/4 of a inch in diameter with bronze bushings for bearings. Any information would be helpful.