Has he tried to find the lost private key to the bitcoins at https://bitinfocharts.com/bitcoin/address/198aMn6ZYAczwrE5NvNTUMyJ5qkfy4g3Hi in some other way ? As I understand the privat key he lost looks like this 5Kb8kLf9zgWQnogidDA76MzPL6TsZZY36hWXMssSzNydYXYB9KF but only the first digit "5" is correct, and the next digit is K, H or J