I'm not sure that you can diagnose a learning disability based upon IQ score spreads. The two deviation discrepency that is used to dx a LD is when you have two SDs between ability and achievement, not various ability subtests. That is not the say that the OP's child isn't 2E. He may be, but I don't believe you can say for sure based upon IQ spread.
Anecdotally, both of my kids have some significant spread on IQ tests. One of my girls may be 2E although I have had two psychologists assure me that she is not. She is the one with the more significant variations in IQ like the OP's. The second of my girls also has one low avg subtest on the WISC and three gifted subtests. Even within those gifted subtests (those that came out in the upper 90s total), her scores varied from the 25th to 99.9th percentile. I am as certain as I can possibly be that she is not 2E however.
eta:
This article on best practices in identification of gifted students with learning disabilities might be useful to see if 2E is something to consider.
