Hey, you know, I couldn't leave this one without commenting.
Belle, this is what I tell every parent who is coming to me for OT whose child has the same problems.
First, focus on learning without writing. Accommodate the handwriting deficit in order to keep his love of learning alive and his learning moving forward. Think of it this way: if he had a clear physical disability that absolutely prevented him from writing you would accommodate and do dictation, voice activated software, etc. Do that for him now. Allow him to "show the work" in whatever way is easiest for him.
Next, address the underlying issues that contribute to his handwriting deficits. Doing fine motor drills is fine if the problem is fine motor coordination. But I suspect that this is not the *underlying* issue. My professional experience is that handwriting practice does very little to help the problem when the underlying issues aren't addressed. It's sort of like treating the symptoms of an illness but never addressing the cause.
I know you've said that you are not able to access an SI experienced OT in your area. Is there any way to at least get a really good evaluation and consult that would help you structure some home activities to address the hypotonia and dyspraxia? Can you find a Therapeutic Listening provider that would do the program on a consult basis, without seeing him directly except maybe once or twice a month? The program isn't really designed to be a stand-alone treatment but it alone is better than no SI based therapy at all.
Another approach to take, since you say his hands get so tired, is nutritional/biomedical treatment of the hypotonia. He most likely has poor postural stability through his core, from shoulders to hips, as well as in his hands. See if you can find a nutritionist or physician who understands nutritional treatment for low muscle tone. I find that kids who up their protein intake show good improvements in overall strength and endurance. Just a protein shake daily can help. A more structured program that includes B complex, E complex, L-Carnitine and Co-enzyme Q10 can help even more.
In the absence of being able to improve the actual mechanical production of handwriting, accommodation is the way to go. You are absolutely right, IMHO, to remove the demands of handwriting from his schooling.
