OK, it’s not done yet, but it’s close enough that I just had to share a photo with my NB comrades.
As you can see, the frame is constructed of simple untreated pine, 2x4s and 2x6s. The surface upon which the kettle sits is perforated angle iron. I put a considerable amount of distance between the side framing and the burner, since wood is obviously flammable. I’m also going to enclose the burner in a steel heat shield and also line the inside of the wood framing with concrete backerboard to further protect the wood from heat.
I tested the stand with 14 gallons in my pot and it showed no signs of failure.