I am still working with this dataset. I have an idea for some "grand" mosaics combining more image data and hopefully doing better with the terminator. I have, however, fixed the unnatural limb, and some hazes are visible. I am posting this today in honor of the 25th anniversary of Voyager 2's flyby of Neptune and Triton.
Here is an enlargement showing some of the atmospheric features visible.
Processed image Copyright Ted Stryk, Raw Data Courtesy NASA/JPL