I don't think I've seen this before, so I'm intrigued
This is all I know about weird private key formats. Your HEX string is 68 characters, if it would be 64 you could enter it into Bitaddress.org's Wallet Details tab to get the address and WIF key.
Are you sure this is non-custodial? If it isn't, you can't possibly recover it without the current owner (Coinbase).