Front Frame Rail Rot

It looks fixed. You come closer to keeping a square car and alignment that way too. Time and pot holes will tell.
Wire feed welders, or any for that matter, take practice. We all tend to run the heat and wire feed rate too high. Its best to start at minimums.
The goal is to move slow and really melt/wash/nit to pieces rather than pile up material like so much chewing gum.
I"m not suggesting your welds aren't strong enough or I could do better.
Carry on and happy moparing. :)