I am in the process of replacing my king pins, while doing that I wanted to replace some rusted out areas around the fenders. Most of the parts are 90% there, a few areas need some replacement strips welded on.

What are the specs on the original metal around the fenders? I am using a flux core welder, any recommendations on wire type? I was thinking of using 304 SS replacements to help prevent them from rusting out again. Has this been done before, or should I look to just match the original metal?