Thanks mate!!
In my opinion, the panels are cheap. So worth having a go.
Once you get the replacement panels, you will be able to see where to look for spot welds.
They run right around the entire edge of panel.
The new panel is just an outer skin, it will fit upto the inner panel.
Then needs spot welding to fuse the two pieces back together.
YES, you will see the line where new panel sits against inner panel.
That original photo is below the ute rail and tie down points I think?
So yes it will fit the same way.
I put seam sealer on after I finished spot welding.
Below the ute rail and down the door frame too.
Seals it up and looks almost factory.
Any auto parts place or bunnings hardware even sell it
I also decided to smooth the line joining rear quarter to tail light section.
It only needed a skim of body filler to tidy up.
I use GAS MIG,
I can't see why gasless wouldn't work.
For working outside, gasless is better.
You wouldnt have to worry about the wind blowing your shielding gas away.
Good luck with the spot weld drill bit.
I hope this helps you

Cheers