Much better, now try and put two pieces together side by side or stacked ontop of each other. The outside corner weld on thin metal is tough. Lets do something easier, to get the basics first. Good thin is that looking on the inside of the box I can tell that you got a good burn in a few spots. The outside corner will melt away pretty quick, thus your heat and speed at which you pull the puddle has to be a little more controled. Slow on the outside of your arc and faster through the middle.
Now get two pieces about 6" long, stack one off set from the other and lets see what you can do on a flat straight run.
You keep wanting to do the toughest things first.... man, I've been there..

way to stick with it.
Your welder is great, I have had the same cracker box for over thirty years. If you have it set on 45amps to weld, you need to change rods size. Get a small box of the different sizes and play with them to see what your machine likes on different thicknesses of metal.