Today, after five frustrating hours, three minutes before the archives closed, I found this: the first EVER piece of hard documentation that Peter Philips died in 1628. And, thanks to this little piece of paper, we can say with certainty that it happened before October 2.
It was all I could do to keep myself from hunching down in my chair, drumming my fingers together, and doing a Mr. Burns-style evil cackle. "Smithers . . . at last . . . 'La meurte de Pierre Phillipe.'"