i think he speaks some English, he posted a couple of times on the RX boards before the pirate forum had a 10-post limit. maybe he'd even post here if someone left a comment on his blog or something.
i can't quite tell from the google translation of that blog post though, but it seems to me like he dumped the menu from some other cart in 2001 and made his own version using its code. and my 19 in 1 only has games from 1999 or earlier, so I'd guess it was made before '01.