Historical Significance Tax Exemption

I read this thread. with interest, when I purchased my Ercoupe at the end of May. I guess I got lucky - living here in Delaware we have no airplane tax. I was surprised and, of course, happy to find that on the State website.

Robert 3800H was often shown in Ramona and they wrote up the paperwork.

It's actually the county the handles the annual property tax. San Diego County is pretty strict with their scrutiny of the form, making sure the plane isn't exhibited on two or more events on the same date, and that each date is signed off by the event coordinator of that particular exhibit event. An exhibit event is not limited to your home airport and can be a good excuse to fly out to other airports for their exhibit day.

Does anyone here do the Historical Airplane Tax Exemption in CA? I filled out the form last year and have my airplane tied now near the Flying Eagles event which happens every month. It gets looked at, of course, since it is an 80 year old airplane. The extortionists, I mean taxmen, want me to provide a signature from the event coordinator. Technically, I am the even coordinator of my own airplane... My question is how strict is CA about this? The event is advertised but I just cannot get the actual event coordinators signature. 

Most states, as far as I know do not play this game and just give owners of Historical airplanes a break, as it should be.