Richard Nixon Autographed Note

I have a handwritten autographed note from Richard Nixon obtained by my father when he was national treasurer for the Veterans of Foreign Wars. The note states, "Best to Roberta from Dick Nixon". Unfortunately, it is not dated. However, based on the photo of me attached to the note, it could be dated sometime in the mid-1960's as I am about five years old in the photo. The note is written in ballpoint pen on a piece of plain green notepaper.