Interesting you mention the gap...
I finally got ready to use my mill last night, but I had already been messing with the gap adjustment, so I knew it wasn't "factory set" anymore. I got my feeler gauge (I have a pretty nice one since I used to work at an auto restoration shop) and select .038 as a starting point. For the LIFE of me, I could not get the rollers set! I'd turn the adjustment knob so that rollers were snug against the gauge, and then tighten the screw. First, it would almost instantly spin the adjustment knob on be, so I was trying to hold the feeler gauge, the adjustment knob and the tightening screw all at once... When I would finally get it set, I'd pull the feeler gauge out and then for the life of me, couldn't slide it in again (right, right - have fun with that one...)
And when I'd get both ends set, I'd often have the same problem - the feeler gauge would "fit" at one end, and not at the other... It was driving me insane. And then I noticed something... I spun the free-wheeling roller by hand and watched the gap betwen the rollers... IT MOVED. The free-wheeling roller is NOT center on it's shaft. As it spins, the gap changes. I can't tell you specifically by how much, but if I had to guess, it's at least 3-or-so thousandths of an inch. Definitely enough to see by eye.
I don't know if something like this is normal, or what. I also don't know if it's worth bugging Millars about or not. I mean I realize I'm only crushing grain here, but what the heck do I set the thing at, and how will I ever know if I'm on the "tight" or "loose" end of the spectrum...?