Okay, a late report on my results. The brisket turned out much much better than my first, although it was not the great I'm shooting for.
My recipe said 6 hours on the smoker @ 250, then wrap in paper and back on until the IT was 200. That took a little more than 3 more hours. At 200 degrees IT, the brisket passed the toothpick test. I put it between two towels in my ice chest and let it rest for two more hours. The party I intended on bringing the brisket to wasn't until Sunday at 1, and I wasn't sure what else to do other than wrap it, paper and all, in a couple layers of tin foil and put it in the oven at 170 degrees.
At the party I unwrapped it. It was done, and tasted great, although it was dry. The folks at the party scarfed it up pretty quickly anyway in bbq sandwiches.
The bark wasn't as dark as I'd have liked, and I didn't see much - if any - smoke ring on the meat. I need to work on that. I'm sure not sure if the dryness was strictly because of the overnight in the oven, or if I need to change something else.
I learned a couple of things though. One, if I'm going to do this recipe with the intent of having it for dinner that evening, I'm going to have to start very early in the am. And two, it's going to be really, really good when I get it right because this not right was pretty darned good.