Can somebody help me with the value and scarcity of a 4006 CHP TSW with a rail that is built into the frame, it is not one of the black bolted on rails.

Price wise, I would imagine that they are in the same neighborhood of other 3rd Gen Smiths TSW pistols with the integral accessory rail. Number wise, I'm not sure. There are roughly 7300 uniformed employees in the CHP so that many and a decent supply of spare pistols.