With dysgraphia , even with the OT, it is likely that the act of physically having to coordinate written output with composition is part of the problem. Does he like making up stories, or telling you about things that he has learned or is interested in? If so, maybe you could act as scribe or secretary and type up things of his own choosing that he narrates to you, or have him narrate them into a recorder and then have him type or write it up going from the recording. Breaking out composition from the physical act of writing worked well for my seriously dysgraphic son, and as he got older, he was more and more capable of putting them back together (on the computer - he still can't compose for beans or write legibly when he has to write by hand). It made a huge difference.
At 14, writing is one of his favorite subjects, and he has a gaming and fantasy/SF blog which has numerous adult followers, most of whom aren't relatives.
It is something to think about.
