A: It contains Marcus Brody's sacred blood. If turned into a missile, it could level armies. That's why Marcus died of a heart attack. (Hey, ask a stupid question... )
Q: Henry Jones Sr. couldn't have died by 1957. He's an immortal wizard. Did he abandon everyone and start over when people would assume he'd be dead?
A. Apart from slightly kinky coat hangers he collects the ears of his victims which he wears as a necklace and he also collects limited edition TY teddy bears.