Shift,
I understand the love that we have for our souls in animal bodies. They are truly the epitome of how we should live our lives; love unconditionally, always be selfless, stay present and not dwell on the past or worry about the future.
It sounds like Sir William had the most loving home, a wonderful life and mostly, a human who loved him the way he loved you. Just as lucky as you are to have him in your life, he was as well. Dogs are saints and we are lucky to call them friends, family and our soul mates.
William has changed his form, but he has never left, he will always live within you and it is so amazing that you have been sober and are able to be present and honor his life consciously. He deserves that and so do you.
I truly believe that, as the movie so smartly said all those years ago, ALL DOGS GO TO HEAVEN. Heaven is in your heart, your memory and the eternal love and connection you have for each other.
I am so sorry for your loss and I will say the Jewish Prayer for him tonight.
Nic.