If I understand correctly, you've replaced the "misty" (kasumi, no 't') finish with a mirror finish, is that correct? Pics would help. If so, you may need to use natural stones to get back the misty finish.
TS; There is no "katsumi line" or even "kasumi line" If you talking about habuchi/hamon it's no big deal, a finger stone will fix that easily.
If your talking about the shinogi, then you may be in trouble!
Some terminology here; http://www.samurai-sword-shop.com/blog/the-tip-of-the-katana/
As said, some pics would help.