I have to agree that it's not and never will be a pretty fish. BUT, most everyone has an ugly fish that has sentimental meaning to them and they keep it just because. If you like this fish, then by all means keep it until you tire of it or it passes on.
Just because it's a mutt doesn't mean it won't grow. I have the ugliest Kohaku you'll ever want to see, spawned in my pond naturally

and she was 28" in May. She grows 3-5" a year. She's not particularly friendly but I keep her because she's huge both in length and girth.

She also teaches the others how to push the rod on the auto feeder.
I also have a 30" longfin that is speckled. I keep her because she's 19 years old and my first fish.
I've moved up the ladder a few rungs in the hobby and have some nice fish. Keeping the fugly ones for sentimental reasons just means you either build more or large ponds or you have to sacrifice a better grade fish. When it's time for you to move on, you'll know it.