If the pliers thing doesn't work, you don't = want the velcro solution, and your canvas is in pretty good shape, I'd = check with some camping stores to see if they can recommend a good tent = mender.  You would probably have to remove the canvas to get the = work done and put it back on afterward, but I've had good experiences = having zippers replaced in tents by folks like these -- you'd never = know it wasn't the original. (I can even recommend one in Ottawa, = Ontario, if you want.  Haven't had to do anything like this since = moving to BC three years ago.)

Kath, Rob & Vanita (87 Westy)
North Vancouver, BC.