BTC were then purchased with a small amount of cash from a bank account on a website I dont remember & then transferred to the wallet. All this happened within a few months of the "infamous pizza" story first making the news so it's 100% all happening in 2010.
Imho you should think it over again and find better clues about the year, since I don't think that you'll find any wallet in 2010 that was handling words (no matter if seed or brain wallet). All that came later.
And if your story is inaccurate you will get answers on BIP39 and such.
Also, after clearing up what year was it, maybe you remember what wallet you've used; it could be of real help. If it's indeed words-based and local (so I'll cross out blockchain.info), Multibit and Electrum would be the main options, but both came at the end of 2011. I think that only Bitcoin Core was there in 2010 and it had no seed words.
Without better info, the answer to your BIG question is "you don't". Sorry.
I've had a quick look into BIP39. Words don't match the list. If we are talking algorithms SHA256 HASH & maybe secp256k were mentioned. May have everything to do with the blockchain & have nothing to do with anything wallet related.
The whole brainwallet concept may have been used but finding information on the programs used but im almost certain it was Bitcoin Client. There is the paperwallet option as well but moving the mouse around didn't tickle my fancy so I did it another way.