No clue about Peter Lyon. We were climbing up there before the trail came from the lake parking lot. Used to access it from below where all those nice McMansions are now. But I have to admit that the lake trail is much better access.
Since you're local (sort of), if you want to do some afternoon bouldering and TR's, I've got a spot up in the hills behind my place that'r kinda fun. Gimme a shout.