Thanks for the information on the cold start valve. I'll try to check it out without blowing myself up. As far as the fuel distributor goes, it would probably would have been an expensive roll of the dice, but I bought it used from another forum member. He bought it to try to fix his 420 SEL, but it turned out to be a valve problem.
This forum is the best I've ever been involved with.
1986 560SEC: 150,000 miles, runs great, but I've got to sell it (too many cars for one man)
1987 560SL: 122,000 miles, used to run poorly, now (thanks to forum), runs great!
1997 GMC Jimmy: Turned out to be a turkey.
1989 T-Bird Super Coupe: 150,000 miles, still runs great. Ford got it right.