Rust Issue

[GeorgeLeonard]

The other day I removed all four fenders from my 1966 Chevy short stepper. I think its really cool that I can do that and still drive the truck on the street! But let me tell you, that it is not an exercise for the faint of heart if you have any rust issues. My picture shows what I found. Im glad that a picture is worth a thousand words as I dont even know how to begin to describe it except to say that it is a mess. Obviously, this part is ruined and the worst part is that the rust looks as if it comes from the inside so that any external repair probably will not last very long. But what is it that is rusted? What function does it perform? What are the ramifications of not fixing it at all? Will my heater still work? Is there any way to repair it besides cutting it all out and welding in a replacement? Where would you even get a replacement except from a non rusted parts car? Anybody have an words of advice or consolation? I never even knew about this until I took the fender off. I almost wish I had left it on.