Body/paint floor questions

Hi all, can you take a look at seam on floorplan in pics. I'm not sure if this looks good/correct? It's a complete 1 piece AMD floor pan. Similar scenario with trunk pan.
I want to protect the underside, but have run out of $$ to pay shop to do this.
Pan still has AMD "coating" on it. Any ideas what I can do?
I have a mig welder but no space and very little welding skills lol, but am willing/wanting to learn.
Thanks
Steve