I thank you guys for chiming in, it not only motivates but encourages me to keep going with this project. I think, besides being considerably more time consuming, buttwelding with a mig welder requires clear access to both sides (upper and lower floor) and I have limited lower access plus it requires near expert fitting of the panels. I know some guys out there have either mad skills or have been doing these kind of repairs for years and are very experienced experts but I am far from a expert in the required skills department lol! This is a patch and if this was some rare model car I would buttweld and probably replace the section completely. I plan on using small sheet metal screws to hold everything together and tight before welding and, of course removing the screws and filling the holes. Copper
Common sense, the least common of all the senses. Mom.
For fear of ridicule, society stifles creativity. Ricky Valdes
with a mig welder requires clear access to both sides 
(upper and lower floor) and I have limited lower access plus it requires near expert fitting of the panels. 
I know some guys out there have either mad skills 
but I am far from a expert in the required skills department lol! 
This is a patch and if this was some rare model car I would buttweld and probably replace the section completely. 
I plan on using small sheet metal screws to hold everything together and tight before welding and, of course removing the screws and filling the holes. 
