AU for sure 53-55, but wouldn't be surprised if it got a 50. There appears to be wear on the crown and wreath leaves directly opposite the crown (EDIT : Tiara] on the reverse. I believe that could be a weak strike in that area, but what do I know......
AU 50, I can see enough wear to knock it down. The large cents in the 1850's were struck fairly well. I see a lot of wear over the ear and the word liberty. Very nice coin though. I'd buy it.
PROOF DCAM70!!! (AU 58) I'm not a great judge of these, but I submitted an 1850 large cent that came back EF45 that wasn't nearly as nice as this one (though it's pretty darn nice).