Thanks polarbear
We have meeting at his school next week to discuss his IEP. I'll ask then if they think he needs further assessment in writing and reading. If they can't / won't assess we're considering a private assessment. So far he's only done the WISC IV (done by the school).

Re: reading aloud - he reads aloud OK but slowly, and often is guessing what the next word would be from the context rather than reading each word.

E.g. if the text said "I went in the house through the window", he may say "I went in the house through the door" (because that's what he expected). But then he'd go back and correct it. So I guess it's possible he's scanning ahead too far.

Intonation is correct unless it's a sentence structure he's not familiar with. Then he stops, and re-reads the sentence over and over until he thinks it's the correct way to read it. (Yes, perfectionist as well)