Thanks for the Heads up @DanyRay, I tried that on the second copy I bought and it still tore, 3rd copy I used a hair dryer on the back cover and it worked perfectly!
Using a hair dryer on hot about 4 inches away from back cover for about 2 minutes and the map fell loose. The another minute or so heating the glue on the map and rolling it into a ball with my thumb and off the edge it went, map & cover undamaged!
Your right about availability, I have not found this in any game store and had to order online.
Hats of to James Jacobs, this is one of the best city supplements I've owned since Greyhawk!