Monday Mutant 83: Polyominous (cipher)

In this Polyominous puzzle, the given numbers have been replaced by letters; all instances of a particular letter represent the same number, but two different letters must represent different numbers. The rules are otherwise unchanged.

MellowMelon recently held a contest to see who could correctly attribute the authorship of the most puzzles out of the 18 puzzles in Fillomino-Fillia, and Projectyl (Mike Sylvia), to whom I previously dedicated a Totally Awesum, won with 16 points. Given that he thought MellowMelon wrote the hard Cipher Fillomino (I actually wrote both of the Ciphers on the test), I am very eager to see how he reacts to finding out that I created this puzzle, as well. (By the way, Projectyl, I authored both this puzzle and the hard Cipher Fillomino from the test. When MellowMelon sent you a preview of the puzzle, he said nothing about actually being its author. Haha! I'm such a delightful prankster! I wonder what ridiculous antics I'll be up to next. Will I temporarily use an ugly color scheme on my blog and claim that I'm no longer posting puzzles?)