Where do you find a "shiny new anodized cover"? Short of building one yourself.
You will have to remove the cover to have it welded, since it's aluminum it will have to be super clean. The crack you have is common to the K5 that has been laid over, Mine doesn't have it, but at least 3 that I have bought have the same problem, I've repaired 2 of them and will do the last one when I get it off. A good welder can fix it as good as new, and a little time on your part, you won't even know it was cracked. 42 is right, you can't have to big a knob on the inside, it will have to be ground down flush, no big deal.
If it is your intention to keep the bike, I would either replace it or get it welded up.