Bahahaaha, how can you say that harry wouldn't have heard of Warwick Park... it's still quite well known.
Just because you or your friend has been there and done that it doesnt mean that you are all-knowing. My old man (who is the same age as you) was racing GT6's and Spitfires at Mallala/AIR/Winton/Oran Park/Phillip Island/whereever in the 70's and 80's and he was very quick but I doubt he could be trusted to set a car up. Same with his friend who was running a historic Datsun Fairlady and won the Porsche Cup in 93ish, I doubt Chris could set anything up.
The only one of his friends that I would rely on is Simon Aram, but thats because he was building front running sports sedans and Formula cars for years.
Yes, you have experience and knowledge
but you're not necessarilly always right. You don't always have to jump straight on people who don't agree with you 100% and sometimes you need to check exactly what has been said... Arguing about crossply slicks when someone has been talking about street cars and street tyres is a tad pointless.