I saw your photo before and I reckon it is well. And just because the border-line in your image I tried to reduce it in my photo. I got something, but if you look with attention at the top of Moon, you will perceive an area different near the border , with less sharp.
Registax 6.0 is very powerfull, but not friendly. And in my computer it is very slow to show the result of any manipulation.
I like very much the wavelets. But it is necessary to be careful in use it.
And there aren't tutorial or method to fix well the image. You must try, try, re-try, re-try and try again and again try again !