Sorry I'm never really sure if I should reply directly to people or just encompass comments in a new message?
I hadn't realised that the pictures loaded in the wrong way, indeed the first picture is the back side and the second the top side
The area of the floor is in the footwell under the dash so access is not great so partly the reason for the unsteady hand, that and my lack of skill !!
I am using a Lincoln BesterMig 200-S Multi Process Synergic set at 1.2mm thickness which is the size of my panels
I will try some short seam welds on scrap bits and see if I can get decent penetration before it blows through
The truck is a 1970 Chevy C10, mostly original thus the need for rust repairs!
Thanks again for all the help guys, its really appreciated
On the car isnt the best place to learn. Go buy a couple of used car panels, cut them up into decent size practice pieces, or cut holes etc to patch. Learn at the bench, under the bench upside down. Throw dust in your eyes, try again squashed under a couple of chairs……once your some where near….start on the car!