Admittedly, I do not have Datsun Z etc. I have a 1967 Toyota Sports 800 here in the San Diego area. I would like to see a group like yours participating. Of course, I also would be interested parking with you, since there is no way toyotas would be able to muster many, or any Toyotas. I do have a friend that would display his Toyota 200GT with me to, which would be great to see along side of your cars.
Here is the website info. If someone would organize 18 or more Japanese cars, it would be be a good thing.
Fifth Ave Auto Showcase, Gaslamp, San Diego - 5th Ave Car Show. Classics, Luxury
If not, I will sign up in the "special interest" class and hang out with kit cars and various other cars with no classification.