Here's the initial post from Bobble on how to calculate zonerect:
http://www.eq2interface.com/forums/s...erect#post5883
Because the zone is so small, you might get a more accurate rectangle calculating it by hand than using the zonerect calculator from the site.
However, I don't know if the game takes decimals in the coordinates, so what's there might actually be the best we can do, unless the map were scaled down to 1/4 or so of the size it is now so that there's a bigger space to extrapolate the rectangle to.