Body panel replacement tips/advice needed

Yeah I am not exactly sure which route I plan on going just yet because they each have pros and cons.

If I decided to go with a lap weld as was mentioned I would for one have to pick up a flange tool....which is not a big deal. I would have to overlap the new panel with the existing panel and either pick up some klinkos to aid in alignment or I would have to drill in some self tappers...which is also not a big deal. But the pros and cons of it is that with the lap weld I would have a little extra material behind the panel due to the addition of the flange which would help in avoiding burn throughs....BUT at the same time it would come with the price of having a lip on the backside that could gather rust over time.....sure I could fill it in from the trunk side with some sort of epoxy but at the same time.....with using a lap weld and flange it is noticeably obvious when looking at the back side of the quarter panel from inside the trunk that there has been metal replacement.

where as going with a butt weld its not as obvious when looking from the back side that a replacement had been made and you have the option of grinding down the backside if desired........but the CON of going with the butt weld is the increased chance of burn throughs.

I am thinking that what I will end up doing is pick up some spot weld bits ( I have some somewhere but who knows exactly where LOL).....figure out where I want to cut,draw my line,cut the line with a 1/16" thick cut off wheel,drill out all my spot welds,split the panels, make some replacement trunk drop extension panels and get them welded up into place,get some weld through primer to prevent ant future rust from forming on anything hidden,put my new panel in place and clamp it all down and I think I will end up butt welding the panels in place and pool welds up where the factory spot welds were.

but with most of the panels being accessible from inside the trunk ......I could always take a piece of copper or something and have it on the back side of the panel where my butt weld seam would be and it would act as a weld backing to prevent burn throughs and would also act as a heat sink.

I am just thinking out loud right now lol....just weighing options and figuring out the game plan and gathering info from you guys to see how you have done it and how you prefer doing it and what tips you nay have to share.

Thanks again everyone and keep the ideas and pictures coming!