My understanding, and I don't have a source for you other than I was a bit of a Da Vinci buff ever since I saw the models of his inventions on display at the IBM Watson Research cafeteria as a kid, was that Da Vinci was left handed but as many lefty's ambidextrous. He would paint with both hands and as for writing in his notebooks would indeed prefer to write left handed from right to left. This gave his notes the uncanny ability to be read correctly by the layman when viewed from a mirror. I more weakly recall that Da Vinci had no need of a mirror and was capable of reading his notes back in their original form.
Thank you so much for your input. I have already read your input several times.
I too was taken to a Da Vinci display by my mother when I was a child. I will never forget it. I was too astounded even at that age to see all he had invented.
To this day, Da Vinci boggles my mind. What a great person.
Thank you again for clearing that up about his being left handed and about being ambidextrous. I appreciate it very much.