I had already seen this on FB but it's a great story. Consider the fact that Pete Brock was checking out
your set-up and asking you questions about it! 
What an honor, even if you didn't realize it until a moment later. You met him and you guys had a nice talk. That's what matters. Maybe it wouldn't have been so good if you knew, you might have been nervous.
My Dad had a hot Datsun 240z back in '72 that had a Pete Brock header and full street exhaust on it, man did that thing breathe and sound great. I was asking the old man about it shortly before he died, trying to pull up old memories and he said,
"that thing went like a MFer!" 