Deductions & credits

You may have to use that as the FMV.  Turbotax should really ask for the "cost basis" of any asset, but because not all taxpayers understand the rules, Turbotax asks other things and doesn't always follow up.  If they don't give you a place to add adjustments to the cost basis, then use the adjusted cost basis (FMV plus improvements) when it asks for FMV.