The old-style fretless gut strung hide-head "Minstrel" banjos tuned about 2 1/2 steps flat of where they are nowadays. When you run guts on friction pegs, you'll know why, too.
Oh; and don't use picks of any sort on gut; it tears 'em up, an' they is wickid expensive!

They tended to use a larger pot than modern ones, too; upwards of 13" in dia. or even bigger. They had steel strings in the banjo's hayday - from around 1835 through the Civil War - but they didn't see much use on banjos or guitars for that matter until around the 1880s.

There's a guy name o' Bob Flesher had books and a tape out of old style minstrel banjo pickin' in the old "Stroke" style; sort of primative clawhammer, I suppose. I'd reccomend him highly.

Dr. Horsehair

These primative banjos have a distinctive sound that is not at all like the newfangled "Bluegrass" instruments; one which I like every bit as well. You can prob'ly hear a few tunes on one at the above linked site.