You shouldn't have "damage" if you actually get cash. You'll certainly owe tax, but that's always a given....
The key here is having some records to determine the basis at each juncture and the intervening year K-1's.
The taxpayer always has the initial burden of proof, as if no proof, the IRS will claim zero basis.
*A reminder that posts in a forum such as this do not constitute tax advice.
Also keep in mind the date of replies, as tax law changes.
