The welder who made the repair was beyond impressed with the build quality on the smoker. After he cut out the original weld, he said (and I'm going to try to get this right) that there was no poricity in the weld or metal, so the defect was basically a complete fluke.
He took about 45 minutes to make the repair, and spent another 45 minutes admiring the cooker and asking questions.
As you can see, the welds aren't as pretty as the stacks of dimes the Shirleys lay down on these, but I'm glad to have it fixed.
The repair work pics: