I took what I could make out from the photos and worked up a SolidWorks model of what the OP has been building.
A while ago, I picked out a piece of 1-3/4" diameter steel from the scrap bin. (yes, the boss said I could have it...) I talked to my machinist and we are going to work out a deal with homebrew and maybe some $ for the machining duties.
This is what I have come up with as far as design. The rollers are 1.75 diameter x 6". The adjustment knobs have an eccentric hole in them that mounts the bronze bearing and thus will allow the mill to be adjusted. I have some fine tuning left to do on the adjustment. It actually adjusts way too much right now.
Here it is in full view:
Here is a view sectioned longitudinally through the driven roller.