I was curious about how drawing is affected by this (I recall my ds took quite a while to become at all fluent in writing, and still sort of shuns it... but loves to draw. ) His spelling is perfect, his drawing good, so I guess that he doesn't fit these three categories.

You may have seen this one already, it was interesting to me, anyway:

dysgraphia facts

What are the different types of dysgraphia?
While dysgraphia may be broadly classified as
follows, there are many individual variations that
affect both treatment and prognosis:
1. In dyslexic dysgraphia, spontaneously written
text is illegible, especially when the text is
complex. Oral spelling is poor, but drawing and
copying of written text are relatively normal.
Finger-tapping speed (a measure of fine-motor
speed) is normal.
2. In motor dysgraphia, both spontaneously written
and copied text may be illegible, oral spelling is
normal, and drawing is usually problematic.
Finger-tapping speed is abnormal.
3. In spatial dysgraphia, people display illegible
writing, whether spontaneously produced or
copied. Oral spelling is normal. Finger-tapping
speed is normal, but drawing is very problematic.