Never ever, and I mean ever, clean coins. The only sort of cleaning that is acceptable is if a rare coin has PVC slime on it. You can then dip it in an acetone based cleaner like "Coinsolve", but if it just looks ugly, leave it be. The only coins that should be cleaned are "Encrusted Ancients" and "Sea Salvage".

There are a lot of folks who will buy that particular coin in that (EF) condition. Gear your sale towards younger Numismatists. Younger folk can't afford the high level stuff, and would appreciate a good deal till they can upgrade it. I know when I was a young collector I appreciated the deals that my local coin club got me.