I was trying to think of some simple yet interesting adult books that you might buy and enjoy for yourself yet a 5th grader might pull off your bookshelf and start to read it. For some reason I thought of the book "The Tao of Pooh". I looked at the schoolastic book wizard and it's actually only a sixth grade book. I'm just thinking the only way you're going to get his reading level up to pass that test is going to be by getting him to read. The best way to get him to read is by setting an example and reading interesting books yourself that the whole family might enjoy.
If you think he will rise to the challenge of the extra work in the other school there should be some kind of program to quickly remediate the difference between the level his Ca school taught and the level he needs to be for his Ky school. My mom said my sister had to quickly learn cursive one year when we moved from one state that taught it in 3rd grade to another state that taught it in 1st grade. Sylvan learning center advertises on tv that they can help your child improve one grade level quickly. Since it's almost summer something like that might work out for you to get him lined up with the Kentucky school children.
I don't know what to tell you about requesting retesting.
