No hard and fast rules Mick,patience is a must...along with thick skin.
In my case,I probably had a 1.5 year internet conversation with Henry De Los Santos of CHP and it took that long to make it a happen.
I knew Henry was interested in the car so I wasn't worried because anyone who knows Henry know's he's a man of his word.
He came and shot both Z/28's with his super-duper camera and the rest is history as they say...
Your car is amazing and needs to be published.I'd suggest getting the conversation started and following up to make a reality.