>>56582466We know from the episode of Game Center CX where he visits Gamefreak that they have a physical book that archives all of the gen 1 documents and includes the frontsprites. On top of the pages they dug up for the Satoshi Taijiri manga.
It's just likely digital copies of the frontsprites no longer exist, at least on anything connected to the internet. So there's no way to datamine them.
Honestly, I think the easiest way to get them would be for an interviewer to just ask Masuda if he'd release them. We know Gamefreak isn't particularly secretive about them, since they casually revealed a ton of them for a random manga panel. He probably just doesn't realize people care that much about seeing them.