Handwriting and fine motor/muscle control

Hi!  My 6.5 year old struggles with handwriting.  I suspect he has extra trouble with fine motor and muscle control.  We have been using Handwriting Without Tears, and I have been going slow, just learning one letter per day which only takes about 5 minutes.  But at age 6.5 years old he still struggles with writing his own name properly.  Does Charolette Mason talk about what to do when the child struggles with fine motor muscle control?  I was thinking of trying to do more on the chalkboard and maybe a tray of sand.  I also found a lot of helpful OT  (occupational therapy) exercises to help finger, hand and shoulder muscles prepare for handwriting exercises.  I was thinking of incorporating some of that too – and also more scissor work, drawing lessons, mazes, etc to help.  Anyone have similar struggles?  What worked?  I am worried that I am not doing enough to help my child but don’t want to exhaust him with a bunch of handwriting assignments when he clearly struggles with muscle control.

Oh and one more quesiton… outside of the 5-10 minutes of handwriting, do your children who are learning to write do any other writing throughout the school day?  Even as much as a simple word.  If so what writing do they do in other subjects and how much is it?