That "bagpipe" fix is fugly. Glad I didn't have that.
I found the information about the "SVT Discount" under Duratec Maintenance, and drove up to Tousley after work yesterday to take advantage of it to get a new IAC valve. I got the current revision for a 1997 instead of the version for a 2000. The parts guy there said that there had been several revisions to the 1997 part, so I'm hoping it works correctly. I reset the computer when I installed it, and the idle speed at least is much better now. It was running at 1000-1500 rpm all the time, and is now at 750. It's probably too much to hope for that this will cure my recurring MIL problem. I'll find out how the computer settles out tomorrow.
Thanks for the help, folks.