2. list of words
This must be a seed phrase
I would be surprised to see that somebody has been using seed phrase in 2010. BIP39 seems to exist only since September 2013.
The 64 characters are not in hexadecimal format.
This could have been the private key. If it's not a hexadecimal string it's even more difficult to guess what could it be.
I've seen
this YouTube movie about buying Bitcoin for PayPal from CoinPal and the long string was the transaction ID which doesn't help much in recovering your funds (you can only find from there your address and the content of it).
Maybe you have more information in your e-mail?
Since you said "custody", there may be that you've used some custodian web wallet. I've found on Reddit some names, maybe they'll help you remember something, but those are long gone, together with your money (since in a custodian system you have an account,
they have your money)
Most, if not all, vanished along the way. There was MyBitcoin, Instawallet, Bitcoinica, MtGox, BitFloor, Cryptoxchange and at least a few others. Some were just wallets and some were exchanges as well that people often mistakenly used as wallets.