With regard to construction done in 2000 you don't need to produce any proof since the base year for capital gain has been changed to 2001-2002 so just get a valuer to value your construction as on 2001 and you can keep it as proof of construction now the construction done in 2009 I would suggest if you can find your contractor and get a duplicate bill from him it would be good because I won't suggest you to claim an expense for which you don't have supporting documents or else you can get the contractor write on a notarized statement that he has made construction of so much amount and he has shown such income in his return, only then it would be safe to calculate/ include it in cost.
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