You could make it look like new just wire brush it until clean and put some Paternation oil on it to keep it from going green you can buy it from any roofing centre
Brian Knowles
December 2008
more than likely is copper,if your lead goes white in colour all you have to do is apply patination oil to the lead to give it a protective coating,and it will bring the lead back to its original colour
mike arney
November 2008
That's very strange. It's copper that turns green when corroded/weathered. Lead usually goes grey/white.