Stretching on the grill cloth
There is a lot of ways to get your grill cloth on tight if you look around the interwebz you will see what i mean. I have found a simple method that gets it on real tight and dead straight every time...

Pretty simple really. I clip the cloth onto the baffle across the bottom edge then the back of the baffle. Make sure you have reference lines to follow. Getting the cloth on straight is critical. Clip the cloth onto a board as above and apply even pressure with some decent sized clamps. You can stretch that cloth really tight. Make sure you dont pull it too tight or you will have problems in the corners.
You can see how I stapled it all down. Got a little trigger happy on the corners though.