Deductions & credits

She says she can't find the original purchase agreement (closing statement/1099-S. )  I think you mentioned that we could look it up through court house records.   But I'm wondering if we have used that $159,800 for so many years on the Form 8829, couldn't we take that as the cost basis?

 

And does it further complicate things if we took a Residential Energy Credit in 2011?   LOL   This is a nightmare!