how bad is this rust?

I have done this to my 67' barracuda and I found it is easier and more accurate to replace inner fender and frame rail as an assembly. There
are holes through the short piece that connect the firewall and inner fender together and through the upper brace of the radiator support
and inner fender that the factory used to line them up. the only measurements needed will be from inner side of rocker to outside of the frame rail where it meets the tranny cross brace and between rails at same location and between rails at the front. get the car level and drop a plumb bob floor from the rail at few places and mark on the floor also if you would feel better about it.:tard: