Sorry to hear your DS's organizational struggles. My DS has these issues also, so I know them well. Our school is in the process of creating a 504 for him as I am very concerned when he enters middle school.
I did speak to a mom at our school whose son has obvious focus and organization issues and the whilst he does not qualify for a 504 accommodation, he did get an aide to help him out for a couple of hours a day, and he was given an extra desk next to his to help organize all his stuff. He was also seated next to the teacher. My son is also seated close to his.
My DS also does well academically, so no offers of tests were given during our meeting, but I am going to request that the school do an evaluation. I found that sharing with our school the anxiety that our DS is having due to his issues seemed to get the administration's attention.
I have the Smart and Scattered book too; on my next to read list!