I sent LOR, SASE, and photo on 1/5/17 and on 1/23/17 I received my photo back signed twice and dated as I see is usual with Henry. I included a $10 blank check to donate to a favorite charity of his or to add to his production company and it was returned to me as well.
I used the following address:
Henry Winkler
Fair Dinkum Productions
P.O. Box 49914
Los Angeles, CA 90049
Yes he did. I see that he usually dates his autograph. All I can think of is that he signed over his suit in blue first and it wasn't easy to see by the eye (my scanner did a good job of picking it up) so he signed again.