Well, I had a couple of issues with the gas valves. I had purchased a couple of ASCO valves a long time ago, and it turns out they weren't sufficient. They had a minimum pressure of 5 PSI, so they work fine with propane, but not natural gas. I should have realized that when I installed them. When I first bought them, I was brewing with propane, so I didn't think anything of it. So, I picked up two more of the valves that I had already installed under the boil kettle (from http://www.valves4projects.com) and as of tonight I'm back in business. Just waiting for a replacement burner to install underneath the mash tun as a section of burner tips broke off as I was trying to remove a busted tip with a screw extractor (that's what I get for not dealing with it when I originally received the burner, long, long ago).
It's getting closer. I'll post pics when everything has been wrapped up.