Sounds like a good idea, there was a similar event held at Brooklands for the 25 years.
I would be up for this, and i sure plenty of others will be.
Re Ally pally, I think the orginal room is no longer there following the big fire, but i am sure its worth asking, if I remember though , enquires were made for the 25 year event to be held there, but it was mega bucks to hire.
John - PLOD11