After about 3,000 miles of travel through this land, from Ohio to South Dakota and back...total backstreets way instead of highway, I had no problems with the alternator, or car, for that matter. I am convinced that the only thing needing replacement was the regulator module. Thanks to Dave and the others for the helpful recommendations and comments, and keeping me from looking for problems where there were none (e.g., diode cluster).
My nephew was totally impressed with the "plasma welds" BTW. He said damn, they make these cars to last! Also, if you don't think you have time to tour the country on your next trip using state routes, think it over again.
My drive time was the same 19.5 hours, whether I took the freeways or the state routes. However, because the state routes were more direct, I saved about two tankfuls of gas. And boy, driving for miles right beside the Mississippi was a real treat. The countrside is absolutely fantastic! Try the "long way" somtime...its quite enjoyable.
1985 190E War Pony (still!)