I will be sending this in as part of the ANACS fall special, only because it's the same cost for up to 15 coins, and this will put me at 13, so it's not really costing anything to get it graded is how I look at it, and it'll be nice to have a solid number on it. I agree with all of you; this is a beast to grade, and I don't think I disagree with anyone!
Some AU's are nicer than MS62's. I only try to give a grade as high as I can justify with available information. I'd have to see the coin in hand to go higher than AU.
IMHO, your coin is a slider with an unoriginal surface. Nevertheless, it could go as high as MS-63 if you send it to one of the big two. ANACS and ICG are a bit tougher. I should expect ANACS to grade this coin AU!