Give details of where it is held, day of the event and time, your details and so forth.
They are very co-operative and it makes them view the enthusiasts and private displays more highly.
It will also mean that if (heaven forbid) something happens, when they get the call, they will bring substantial back up to deal with it.
It helps you as in you will have already notified police, so complaints about the noise should have no issue as they will know its you!

So yes please do it, did it today, very helpful and friendly and were all too willing to help.
Richard.