I can say that it's pretty normal for gifted little ones to have very little interest in 'making stories' if they have to handwrite them. I would work at home on teaching touch-typing, and I'd get the camcorder out and make tapes of your son telling stories, so that your son can start to learn about 'writing' without being bottle necked by the physical act of writing.
Is the test accurate. I have no idea. It would be interesting to ask the tester what the non-verbal section of the test would have scores without the 'what's missing' portion. Over time, you'll have a much better picture of what's going on. Your son wouldn't be the first kid to loose points because he 'went deep' on an IQ test. They aren't perfect tests.
You might also want to hothouse the printing - if so, I love the 'Handwritting without tears' products, and wish they had 'Spelling without tears' to match!
Love and More Love,
Grinity
