Ellis and Jenkins are both excellent guesses.
Both are incorrect for the same reason. As of the start of '79, each had only pitched for 1 NL team (Pirates in Ellis's case, Cubs in Fergie's case).
So if you think about it, in order to have accomplished this feat, you need to have pitched for at least 2 AL teams and 2 NL teams (as of the start of the 1979 season, which rules out Nolan Ryan for instance). And of course a long career.
One I expect everyone will get with a little thought. He is a hall of famer. The second may take a little time, so I will give a hint if no one gets him soon.