If this was a really old Bitcoin wallet, it could be from before the "12 words" thing. IIRC, older wallets randomly generated each key, instead of deriving them from a seed passphrase (which also meant you had to be really careful with your backups, since an old backup of the wallet wouldn't have its newer keys).

I am sure you’re right. But you could just send the funds to a new address in the new wallet. He could have done that at any point in the last 5+ years.

Would he want to have all the funds in 1 wallet?

(I understand these hardware wallets let you load up as many as you want.)

He was more or less doing that already anyway. He could at least have used an even moderate amount of modern Bitcoin opsec.

And one day you hit your head and can't remember the words anymore.

maybe buy twelve items that represent the words and have them around the house

I saw that movie!

What is the movie?