FWIW if his school performance is what you would expect for his IQ I wouldn't worry. Keep it in mind if problems come up but I wouldn't stress.
My DS had similar WISC scores when we tested at 6.5. We tested because he was really struggling in grade 1 with writing, average or below average in reading and his marks were not great because he wasn't doing anything at school and yet we knew he was smart. In his report the tester put "probable LD". He's now 8 and has made great strides with writing and reading but I do think there is something there. He has always been the type of kid that needs time to mull things over, quick thinking is not his thing. Talking to him you can see the gifted side but if you look at his writing samples he looks average at best.
My DS also has a gifted classmate that had low processing scores. His school work doesn't show it at all and it is more likely due to perfectionism or a tester giving poor instructions - he was told to "be careful" so he was. His report doesn't mention anything about a potential LD.
I should also mention that "getting help" in our situation has mostly been things like allowing extra time on tests, scribing written work and some extra patience from the teacher. These things have all helped reduce DS's frustration but it isn't like there is a cure or program we can do to improve it (at least as far as I know.... if there is I would love to hear about it).
