Without the data files, the TurboTax software won't do you any good. And the software older than 2020 won't work anyway. The amended returns will have to be prepared on paper forms. Since you used the TurboTax CD software, TurboTax does not have copies of the data files.
My recommendation is to pay your tax attorney to prepare the amended returns, or have a local professional tax preparer do it in consultation with the attorney. You will need paper or PDF copies of all the original tax returns, or tax return transcripts from the IRS. With your permission, the attorney or tax preparer can get the transcripts if needed (though 2016 may no longer be available).
The attorney or tax preparer may be able to use their professional tax software instead of paper forms, at least for the more recent years. The amended returns for 2020 and earlier will have to be filed by mail. The IRS no longer accepts e-filing of earlier years.
