Good one!
Experts... I could write a book about them. Not only Porsche ones, but every kind of "experts". In my job for example, I have had to deal with quite a lot of them.
There's something I can say: the best ones I have met are humbles peoples, with a boatload of knowledge. They NEVER pretend to have the definitive answer (even if, that's what you'd like to hear sometimes). Another common point, these guys will share, and educate you. And they can do it for hours...
Of course, in every domain, the guys will charge you, especially if they're helping you solve an issue. But they won't be secretive, and give you drop by drop.
THat being said, there are a few guys in this forum who in my eyes are true experts... Uai with the seats, Hugh with history, Weidman for the wheels, DaveP with the numbers, Breazle with parts, EdMayo, Franck Beck (bad taste joke expert), there's another one whom I remember reading electrical posts with passion (I hate electrics!) plus many, many more: bolt finish, 67's specificities, R chassis numbers and races, 901 specificities, lights (Audette), repro (Soterik, Marek)... And there's another person on the board, who wants to remain discret who is probably more knowledgeable thant Jurgen himself regarding plastic Porsches...
None of them spares his time answering questions here! That's my point! None of them is bling bling like many self proclamed experts in the P world.
I saw Jurgen Barth in a classic car race event near my house maybe 3 yrs ago (Circuit Paul Ricard, france). He was driving a car from the Museum. Impossible to get close to him.
Last summer, I've been to the same place. Ari Vatanen was there (he drives for BMW for classic events). Never saw an humble and friendly guy like him! Under covid circumstances, he crossed the border separating the guys with the big cars, busy drinking champain (literrally!) in the VIP hospitality, and the public, and he remained here for an hour or so, taking pictures with people. Always a kind word, always the smile...
This guy is a motor racing heroe.
https://www.youtube.com/watch?v=RS73N7vHRHQ