Welcome dagobbz! I am no master at scores here, but i'm sure someone else will chime in. Here is a nice chart showing different levels of gifted based on scores from the various iq tests:
Hoagies: what is highly gifted Your DS's 139 falls into the (HG) Highly Gifted category. And from what you've said about not cooperating for some parts of the test and the ADHD possibility, you could be dealing with a lower than expected score due to that. The 18s could also be ceilings - i think those are the highest numbers you can get in some categories (someone with more score sense please correct me).
It is wonderful that you have a have a friend who works with 2e learners. That will come in handy when your DS is in school.
Again, welcome!
