Blockchain.com used to send a wallet.aes.json file back at that time. Take a look at the e-mail folders (or another e-mail accounts) that you used to create your wallet.
I confirm I do not have any emails from Blockchain AT ALL.
I checked everything in my email THOROUGHLY, but I cannot find any records from Blockchain, not even the registration email.
Yes I can see other emails from back then, but nothing related to Blockchain.
The fact that Blockchain actually provided me the account password using mnemonic phrase is itself a miracle tbh though.