Thank you so much, onthegomom and master of none, you bring up very good points! I do need to submit by August, and I do wonder if there is some kind of LD besides some attentional issues to explain why there is such a gap between his verbal reasoning and his ability to read, and why he finds certain visual-spatial tasks so difficult (though his score was 75% for these tasks in the Wechsler). The neuropsych who did the assessment chalked his reading lag up to impulsivity and attentional issues and said her son had very similar scores and also read at grade level until he had enough sight words to take off. DS's writing is also grade level, master of none, though when he dictates his syntax and vocabulary are much more sophisticated.
I have another question, since you all are so helpful and it sounds as though he would benefit from testing! The person who offered to test him is his tutor, who specializes in learning disabilities and is a special education advocate as well. By her own admission, she is much more accustomed to working with kids on the opposite end of the spectrum. I've heard people say the test administrator should be familiar with testing gifted kids. Do you think I should find someone else, or should I stick with her so she can help potentially identify and help with any perceived learning disability? In tutoring him, she hasn't noticed anything that she thinks indicates a LD. She is amazed that he mastered subtraction with regrouping in one session and she doesn't seem to be able to retain the information that his processing speed is comparatively very low.