Sounds like I was lucky.
It took me about a minute to bend the door in shape and that was it......
This was my experience, too. Make sure the sections are not out-of-round before you go to the trouble of adding gaskets - you may not need them. The WSM doesn't need to be completely air tight to work right. If you can control your temperatures, and if shutting the vents causes the remaining charcoal to extinguish in a reasonable time, then (in my opinion) it's tight enough.
I measured across the diameter in several directions. If it's out of round you will find one diameter that is the largest (and the smallest diameter will probably be perpendicular to it). Gently pushing inward on the largest diameter - the "bear hug" - will shorten it and probably lengthen the smallest diameter. Go slowly, and measure frequently until the diameters, measured at several points, are equal or as close to equal as you can achieve. Do the same with the lid and base, if necessary. You could also put whichever section you are checking on a large sheet of paper and trace around it. Then rotate the section and compare it to the traced outline. If it is perfectly round (highly unlikely) there would be no gaps between the outline and the actual object.What steps did you take in knowing that your WSM is not out-of-round?