I was about to propose a brainwallet of those 8 words and the 13+ symbols password as BIP38 encryption of the private key, but unfortunately the BIP38 part doesn't fit into the timeline setting as BIP38 was proposed somewhere in November 2012 and thus too far into the future with respect to Bitcoin's pizza day inception.

But the brainwallet could also have been generated from the 8 words and the 13+ symbols password.

I did only a very brief search when brainwallets were invented. I'm not sure if there's a particularly specific period of their inception. Probably many people had the idea to just hash "something" with SHA-256 to get a private key where you'd only had to check it falls within the bounds of valid private keys (being out-of-bounds is very ... very unlikely). And some if not many might not have made a fuzz about their brainwallet idea.

I'll leave my brain farts at this...