Steel. I had an 80s Schwinn Madison, a Falcon road bike(fg), a Pinarello, and one of the *** metal grey Bianchi pistas...all fg. Always bullhorn. My favorite cranks back then we're those Doteks you could get from danscomp, any length, any chaining you wanted. They weren't pretty, but they were cheap and lasted long. 12$ GT bmx platform pedals with the reflectors popped off to take toe clips. That was my "set up" for dealing with Cleveland's awful weather, and worse roads for quite a few years.
Awesome man, that Madison was probably a sick looking bike. I love the older Madisons, I would definitely go with steel for working as a messenger too Rode an older Leader 735tr for a little while, was nice but not for me.