home improvement deduction for home sale

[akores]

My 92-year-old relative has a house that he bought in 1969 and just sold in 2024. He is eligible for the $250,000 exemption for the house sale. However, he sold the house for $100,000 more than that. He has had many home improvements done since that time which we have noted. However, he didn't save receipts from improvments for the last 55 years except for a few recent ones. Not sure anyone saves receipts from that far back. Any advice on what can be done here? 

[Bsch4477]

If you're missing receipts, you may be able to use bank account statements or credit card statements as alternative proof.