I don't know if the wallet.dat encryption at that time existed on Bitcoin Core but I experienced this before I think around 2015 or 2016 my wallet.dat was human readable when you open it with Notepad but if the encryption existed before then it depends on the OPs wallet file if it is encrypted or not but if not, he can't able to see or understand it's content.

@OP If you need professional help why not contact walletrecoveryservices only if all recovery methods you did do not work you can use their service and provide only the hash of your wallet.dat passphrase. Check their thread below

- https://bitcointalk.org/index.php?topic=240779.0