Weird Honda didn't seal that bit as it's where most of the crap/spray from the wheels lands! Loving your fabrication skills mate, looks so much better with that pitted area cut out and replaced with fresh steel. one less area to worry about now!
Deffo inspired me to learn welding, might look at getting a course in the new year. Is it a mig welder you've got and are you using gas or gasless? Got so many ideas/jobs (not just for the cars, some stuff for the garden and garage too!) where being able to weld would be amazing.