I think I might first hunt around the school district website and see if anywhere they talk about procedures or policies for gifted education or early entrance. It may give you an idea of what your possibilities are. If you don't find anything, maybe call the school and ask them what the policy is and see where that takes you.
Just my two cents, it is hard to say whether the school would be receptive or not.
Good advice, but a word of caution: sometimes written policies and procedures are very different than practice.
