I'm a bit confused, were there pits under the edge of the frankenweld that needed filled in after you ground it flat? Did your buddy use stainless weld wire?!
I think regardless of what you do, you're going to always have some kind of discontinuity at the edge of the frankenweld after you grind it flush. It might be able to be hidden with a good rebluing, but it'll always be there if someone looks hard enough. Not to say that what you have is not 10X better looking than the frakenweld wart, I think you did great for your first one!

Do you think a different weld bead layout would have helped hide things a bit better?? I'll be interested to see what it looks like after you blue it. You might surprise yourself with how well it looks.