Thank you, Jay!
That's another good suggestion. The possibilities are almost endless.
After pealing the second clay try, I saw it did this. A crown is nice, but this is a bit much! 
Some differences from the first try. The second was formed on the particle board instead of birch plywood. Maybe it absorbed moisture. I painted the particle board and the second coat is drying. Second, I pealed it off about after the second day instead of the 4th day. This one measured about 4 mm thick instead of about 2 1/2 mm. I'll make the next one thinner like Jeff suggested.
I painted both strips using a mix of burnt umber and red. Then I gave both a wash of a dark gray on the upper part of the strips in this photograph. I think they are pretty close to the local brick streets with minimal effort so far. A little variety in the brick color would be nice, but I don't know if I have the patience for that. 
Another variation is a dull yellow for the bricks. Streets near where our younger daughter lives and around the courthouse have that color brick. I haven't taken any photographs of them.
