So much for the cheap fix....
I went the new rotor and distributor cap route since my cap looked suspect and had a hairling crack around the mounting flange. Other than the fact that it starts up beautifully, it still stumbles at idle and at first takeoff once it get warmed up.
I guess I am headed for a fuel distributor after all-but I may try pulling an injector first. Still only appears to be one cylinder missing a little.