Sorry to hear about your Dad.Since your Dad signed the rough draft Will, assuming that he was of sound mind and had the intent to make it his Will, this would establish testamentary capacity.  He would have had to sign in the presence of the requisite number of witnesses and the witnesses would also have had to sign in order for the Will to be valid. If the rough draft Will was signed, dated, and entirely in your Dad's handwriting, then he would not need witnesses for the Will to be valid.