Looks very good! I am right behind you on doing the same thing but for my drivers side. although you're doing lower section I am getting stabbed in the kidney and going to have to do the entire 1/4 panel *smacks hands to face*
I butt weld everything, or try the best that I can... I finished tacking across the seam, a little hammer and dolly work, and it should be ready to fill in the gaps.
I haven't attempted any outer bodywork welding ... do you have better luck welding at the seam like that? Others I have seen seem to join panels on flats. I imagine it is personal preferance .... trying to learn here.
I'm still learning as I go. When I did the other side, it did it on the flat, but it was a hard spot to comfortably weld, since the car is on jack stands, and I had some distortion, either from too much heat from welding, or my lack of patience grinding, nothing that can't be worked out. My friend that is a professional body man, told me I was making it harder than it needed to be, that if I went to the body line, it has a little more support, and makes for a better finish. Plus after seeing another one done like this, I thought I'd give it a shot. It was much easier, and the finished panel will need less work, to finish off to where I'll be happy with it.
The edge is done, just need to make some rust repairs at the back, and fill a few small pin holes, and I can move on.
That looks awesome! Like it was never cut apart!! My body welds usually have blue rings around them from leaning too hard on the grinder.
I found a few rust spots in the back, under where the bumper mounts, but...I'm almost ready for epoxy primer!