Hey, so I don't know if I might happen to have anything that could help you, but for a while, I've been working on a game set hundreds of years before Majora's Mask, as a kind of prequel. I feel like I've probably had to sprite some things that you'll need, and my feelings on my sprites are that you should be allowed to use them if you want.
I dunno what platform you're working from, but I use rpg maker XP (which is dumb, I know :p), so all the sprites from my game need to be shrunk 50% before they're standard size. But you're welcome to download my game and look at the graphics folders:Game Page
Credit is nice, but really, this is the internet, so who cares? :p
Also, I've been slowly starting to get back into making this game after a break for Summer, so watch out for competition on the Termina front! (Competition/cooperation, if you so choose :p)