Lanse, I think if you took a little more time, you could have made much nicer holes for the smoke stacks and not had to put the patches on. You should have asked for a simple way to mark the holes out.
Considering you could mark the pipe and trim it to fit nice on the inside, I would have used a short piece of pipe to mark the holes. First cut the pipe at an angle similar to what you need for the stack to be vertical. It doesn't have to be exact. Just short enough all around to slide a soapstone on. Then figure out where you want the hole and tack or have a helper hold the pipe vertical where you want it. Then take a long, flat, sharpened on an angle soapstone (out of the holder) and put it flat against the pipe and mark your hole on the head of your BBQ. Put the sharp side of the soapstone towards the pipe. Cut it a little small and you can always trim a little to fit. Would have saved a bunch of work and looked a little neater. Don't be in a hurry to finish your projects. You're not getting paid by piece work.
My welding teacher used to say you need to improve your welding or get faster at it. Very few people can do both. With experience you'll get faster but never compromise on quality. Going fast and then having to make repairs is slower in the long run.