That looks exactly like the same mill used by the natural food store here, which doubles as a small LHBS. The mill they have worked great for steeping grains, but never had the chance to use it for base malts to check the mash efficiency. The only issue I had with it was the hand crank. It's pretty slow just milling 1-2 lbs of malt, so I can't imagine doing 10+ lbs. I would suggest to cut the weld off of the handle and remove/replace it with a power drill, to make things a lot faster.
Get yourself a pound of base malt and run it though there, see how well the crush looks.
I believe the picture us actually upside-down, so you actually have the bottom of the mill pictured. there should be a hole on the opposite side that you feed the grain through, and the whole assembly gets clamped to the side of a table with those "L" shaped bolts.