Hi Guys
I've been out in the garden all morning trying to make a scale model (wood) behave like stone. Don't know what I'm doing wrong Steve but its like a different animal, I can't tame it.

In the end I gave up and grabbed a piece of stone, lovely.

I now going out to buy a dropped curbstone which I intend to reduce to a scale of 1 inch to the foot. Might be able to give you some useful data later.